In order to characterize the pre-launch performance of Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) and Cloud and Aerosol Imager (TANSO-CAI) on the Green house gases Observing SATellite (GOSAT) under the environmental condition on orbit as well as in the laboratory, the Proto Flight Model (PFM) for TANSO-FTS and CAI have been developed. TANSO-FTS has three narrow bands of 0.76, 1.6 and 2.0 micron (Band 1, 2 and 3) with +/-2.5cm maximum optical path difference, and a wide band of 5.5 - 14.3 micron (band 4) in thermal near infrared region. TANSO-CAI is a radiometer for detection and correction of clouds and aerosol effects which might degrade the column concentration retrieval of CO2 and CH4. It has four spectral band regions; ultraviolet (UV), visible, near IR and SWIR. The basic character of TANSO-FTS and CAI, such as the Signal to Noise Ratio (SNR), the polarization sensitivity (PS), Instantaneous Field Of View (IFOV), spectral response, and also Instrumental Line Shape Function (ILSF) have been characterized by introducing the light emitted from the black body, halogen lamp and the tunable diode laser. In addition to these characterizations, micro vibration effect on orbit has been investigated on TANSO-FTS. There prelaunch test results demonstrated that TANSO will provide data for high accuracy CO2 and CH4 retrieval on orbit.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.