FeCrAl alloys wires with different Cr contents were investigated as a broadband radiation source for the spectral region from 1100 to 100cm−1. Due to the change in temperature, the radiation intensity depends on the driven current. Compared with commercial mercury arc lamp and terahertz quantum cascade laser sources, the FeCrAl alloys wires source generates a pronounced THz broad spectrum from 400cm−1 to 100cm−1. Using FeCrAl alloys wires source, the optical phonon absorption and zone-edge two-phonon absorption were observed for typical GaAs substrate transmission. The measurement of the little absorption from 400cm−1 to 100cm−1 for polyethylene film further confirms the potential application of FeCrAl alloys wires source in terahertz field.