UV spectrometers onboard satellites have provided trend data of total O3 for more than two decades. These data have shown the validity of satellite measurements. However, for next-generation observation and to monitor the recent O3 depletion accurately, a high-fidelity spectrometer with high signal to noise ratio (SNR) is essential. For this purpose, the Ozone Dynamics UV Spectrometer (ODUS) has been designed to have higher spectral and spatial resolutions and wide spectral range. It will be launched on the Global Change Observation Mission (GCOM)-A1 satellite in 2006. ODUS covers back- scattered light from 306 to 420 nm with 0.5 nm spectral and 20 km spatial resolutions using a Fastie-Ebert type polychromator and a one-dimensional UV Si-CMOS array detector. The array detector is designed and manufactured specially for ODUS. It has different size pixels and 234 on-chip CMOS amplifiers, which are tuned for each spectral radiance level. ODUS is a nadir-look mapping spectrometer with a mechanical scatter, which can acquire global data in one day. It is expected to provide information about total O3, SO2, NO2, BrO, OClO, H2CO, surface albedo, and aerosol.