Abstract: The device in accordance with the invention is an apparatus for producing electromagnetic radiation for use in microwave resonance therapy. This device provides improved selectivity of the effect produced by electromagnetic radiation in the EHF band on biologically active points. The device is well suited for production by simplified mass production techniques. A continuous spectrum of electromagnetic energy in the EHF band is produced by the device, whose input is connected to a power source via a pulsed voltage generator. The output is connected to a radiating antenna. The source of the electromagnetic radiation and the radiating antenna are integrated together via a slotted transmission line. One of the ends of the slotted transmission line carries a spark discharge source which is connected to the pulsed voltage generator. The other end of the slotted transmission line serves as the radiating antenna.