Abstract: A kind of submillimeter waves Fourier transform spectrometers is presented. The working wavelength is in the region of 33 to 500 micron. The resolution is 1 cm^-1. A microcomputer is used for the data acquisition and data processing. The moving mirror is driven by a liquid-pressure machine in order to get even smooth moving. The displacement of the moving mirror is measured with a laser interferometer. The optical path system is evacuated to prevent the absorption of water-vapour.