The invention relates to a device for generating terahertz (THz) radiation comprising a short pulse laser (1) with mode coupling to which a pump beam (3) is supplied, and comprising a semiconductor component equipped with a resonator mirror (M4). This semiconductor component serves to derive the THz radiation based on incident laser pulses. The resonator mirror (M4), preferably a resonator end mirror, is provided with a semiconductor layer (8), which is partially transparent to the laser radiation of the short pulse laser (1), whose absorption edge is lower than the energy of the laser radiation of the short pulse laser (1), and on which the electrodes (9, 10) that can be connected to a bias voltage source are placed in order to generate and radiate the THz radiation in the electric field.