Welcome everyone to Chroma's 2020 first quarter earnings conference call. All lines have been placed on mute to prevent background noise. After the presentation, there will be a question- and- answer session. Please follow the instructions given at that time if you would like to ask a question. For your information, a webcast replay will be available within an hour after the conference is finished. Please visit www.chroma.com.tw/investor/index under the investor relations section. Now I would like to introduce the CFO, Paul Ying. Mr. Ying, please begin.
Thank you, Jason. Hi, everyone. This is Paul Ying from Chroma. I'm the CFO of Chroma, and welcome to the first quarter of 2020 financial release. Well, I think we have sent all the information to the website, and I think you can fetch that from the website. Let's go to slide number 10. This is the condensed consolidated income statement for Chroma for the first quarter of 2020. You can see from this page, the first quarter of 2020, the consolidated net sales reached to NT$3.371 billion, and this is a 23% growth compared to first quarter of 2019. In there, you also can see that from the consolidated sales of testing equipment for that business, it's a 26% growth on a year-over-year base. Well, on the other side, the MAS operations, it shows that a 35% drop.
For the sales of the new material, for material business, you also can see that it reaches at the NT$559 million, and they represent a 42% growth on a year-over-year base. Overall, you can see that the gross margin of the first quarter of 2020, it reached to NT$1.7 billion, and this is a 33% growth compared to the last year first quarter. At the same time, I would like to identify that the 52% of the gross margin is the first time on the consolidated income statement that Chroma Group reached. This is a pretty good record. I think the major reason is still the product mix of the high-margin portions like the parent company shows a big portion of that.
After deduct the expenses, you also can see that operating income reached to NT$548 million, and it represent a 90% growth compared to last year. In there, you can see that the net income before tax, it's reached at the NT$607 million, and this is a 68% growth compared to last year first quarter. Net income after tax, it reached to NT$486 million, and compared to last year first quarter, this is a 64% growth. It give us the basic earning per share, it reached to NT$1.13. Compared to last year, again, this is a 57% growth. On the balance sheet side, you also can see that there's a little bit growth on the inventory, mainly from the parent company and the cash. It's kind of like a wash of the short-term debt drop and the long-term debt growth.
In there, you can see that the inventory turnover, a little bit over than last year December. At the same time, accounts receivable turnover date is almost the same. Net debt to equity, pretty much the same level, and same thing as the return on equity and return on assets. For the free cash flow, for the first quarter of the 2020, it reaches up to NT$442 million. Well, let's go to the quarterly highlight. You can see from the next slide, the first quarter of the parent company, the sales revenue reached to NT$2.053 billion. This is a 20% down on a Q-over-Q base, but this is a 33% growth on a year-over-year base. The gross margin also reached to, not only above the 50%, but reached at the 55%, which is also a very good record.
The operating margin reaches to 25%, and net income, again, it's reached to NT$ 471 million. Although this is down by 22% on a quarter-over-quarter basis, well, last year's fourth quarter, we did a very good job on the reaching to NT$2.5 billion at the top line. Compared to last year's first quarter, this is a 59% growth. For the first quarter of 2020, the major growth is contributed from the semiconductor and photonics sectors, and this represents a growth of 4% on quarter-over-quarter and 78% year-over-year growth respectively. As to the parent company's income statement, you can see from this page that the first quarter, where again, the net sales compared to last year's fourth quarter, and this is a 20% drop, but compared to last year's first quarter, this is a 33% growth.
Again, the gross margin at the first quarter is 55% and similar to the last year's first quarter, but a lot better than the last year's fourth quarter and reached NT$1.124 million. For the operating income, we reach at a little bit over NT$500 million to NT$504 million, and compared to last year's fourth quarter, this is a 9% drop, but compared to last year's first quarter, this is a 74% growth. Again, for the income before tax, we reach at the NT$567 million. Compared to last year's fourth quarter, it's a 24% drop, but compared to last year's first quarter, it's a 66% growth. Again, on the net income after tax, and we reach at the NT$471 million. Again, this is a 22% drop compared to last year's fourth quarter, but 59% growth on the last year's first quarter.
Again, the basic and earnings per share reached to TWD 1.13. Compared to last year's first quarter, TWD 0.72, this is a 57% growth. For the balance sheet side, again, for the cash and the inventory is still growing. Again, the short-term and the long-term debt is kind of like a wash compared to last year, December. For the inventory turnover, a little bit over, simply because the inventory is still growing, and we're trying to keep more inventory for the future productions and also, the precaution for the broken chain for the supply chain kind of procurement. This is mainly due to that kind of reason. For the accounts receivable, it's pretty similar to last year, December. Net debt to equity is pretty on the same level.
Return on equity and return on assets is also similar to the last year, December. For the free cash flow, for the parent company first quarter, we reached somewhere like TWD 120 million. For the first quarter, product mix and the consolidated sales breakdown, you can see from this page that the first quarter, our traditional test instrument and the automated test system, ATS, reached TWD 1.168 billion. Compared to last year's fourth quarter, this is an 11% drop, but compared to first quarter of last year, on a year-over-year basis, this is a 24% growth. We all know that the last year's fourth quarter, we pretty much made the record high on the top line already.
For the semiconductor and photonics testing solutions, you can see that the first quarter of this year, we make NT$682 million, and this represents a 4% growth on a quarter-over-quarter base and a 78% growth on a year-over-year base. Turnkey solutions is something that, well, for the first quarter, due to a lot of reasons, like the coronavirus and due to the Chinese New Year, it makes somewhere like NT$55 million. This represents an 87% drop on a quarter-over-quarter base and a 45% drop on a year-over-year, simply because last year, fourth quarter, we delivered a big project to the U.S., and that makes the difference. That makes the consolidated testing equipment business reach at the NT$2.57 billion.
This represents a 25% drop on a quarter-over-quarter basis and 26% growth on a year-over-year basis. For AMAS, again, for the first quarter, they made somewhere like NT$177 million and shows a 43% drop on a quarter-over-quarter basis and a 35% drop on a year-over-year basis. For material business, this is NT$559 million on the top line. Shows a 16% drop on a quarter-over-quarter basis, and a 42% growth on a year-over-year basis. That makes the total consolidated sales $3.371 billion, shows, again, a 25% drop on a quarter-over-quarter basis and 23% growth on a year-over-year basis. This is the financial result and also the performance for the first quarter of Chroma Group.
For the 2020 business outlook, starting from the second quarter, we still presume that rapidly development of the AIoT, it's a AI and IoT kind of a combination, increase the demand of the high performance CPU and GPU sensors and RF connections, et cetera, which will be continuously driving the sales growth in semiconductor, photonics, testing solutions, particularly from the several areas like the high reliability testing solutions, burn-in testing or SLT test. Also for the VCSEL and the ToF testing for 3D sensing, also optical fiber communication, OFC testing. Another application will be integrated wireless RF and MCU testing solutions for the TWS, stands for the True Wireless Stereo. The test instrument and ATS for power testing solutions will be focused on green energy, including EV related components, battery module, battery pack, and smart grid on 5G and server related power testing.
Also the In-line Nanoparticle Monitoring System. This is a breakthrough technology developed by Innovative Nanotech, which could precisely detect the particle down to three nanometer and have started to deliver to foundry customers right now. Okay, this is the highlight for the 2020. Now, I'm open to any questions.