In this report, a high-resolution, high-signal-to-noise-coded aperture spectrometer is introduced that replaces the traditional single slit with two-dimensional array slits manufactured by microelectromechanic system technology. The encoding and decoding principle of this coded aperture spectrometer is described, as well as the instrument structure. We then discuss the side-effect, which is caused by sub-aperture manufacturing errors in size and position and the smear noise in the imaging CCD. The side-effect adversely affects the decoding wavelength accuracy of this spectrometer, so we present some effective ways to avoid this phenomenon and to increase the decoding wavelength accuracy of the spectrometer. In the end, we present our experimental results.