The time-domain and the frequency-domain spectra of the terahertz (THz) wave a re generated by photoconductor antennas.Furthermore,the transmissivities for t hree kinds of gallium arsenide (GaAs) semiconductor materials are measu red based on the THz time-domain spectroscopy systems and the method of transmission spectra.The results show th at the stable and the broadband THz wave lying between 0and 2THz can be generated by photoconductor ante nnas.Moreover,the transmissivities of GaAs semiconductor material are almost the sam e when the frequency range of the THz wave is from 0to 2THz,which are relatively high and above 60%.Meanwhile,th e transmissivities of GaAs semiconductor material are higher than those of zinc telluride (ZnTe) and cadmium telluride (CdTe) semiconductor materials. Consequently,compared with ZnTe and CdTe semiconductor materials,GaAs semiconductor material is more suitable for designing the broadband THz function al devices.