On 29th of October, 2018, GOSAT-2 was launched as the successor to GOSAT which is the first satellite dedicated to the greenhouse gases observation.. After the about 16 hours critical phase, GOSAT-2 moved to the commissioning phase and the functional and performant checkout of the bus system in November was followed by the one of the mission instruments in December. The first light of the TANSO-CAI-2 was taken in the beginning of November along with the bus system checkout and the checkout of the TANSO-CAI-2 stared in the beginning of December. The checkout of the TANSO-FTS-2 started in the middle of December. The first light of the FTS-2 was taken in the middle of December as part of the checkout of itself because the about three weeks of outgas to avoid the contamination had been needed. Though a few anomalies had been found in the checkout, it confirmed that FTS-2 and CAI-2 had worked well and all performances and functions met the requirements and the differences from the design were little except the temperature of the band 4 and 5 of FTS-2. All data acquisition was completed at end of December except the system total operation test which is the test using all relevant systems including the ground system and this test was performed in the beginning of January of 2019.