To provide a device which makes a filling operation, etc., of a direct current high voltage unnecessary and generates electromagnetic waves of high output and high frequency.

This device includes a direct current voltage generating part (MHD type explosive generator 10) which generates a direct current voltage, an energy amplifying and storing part (MC type explosive generator 20) stores amplified current as electric energy while amplifying current supplied from the direct current generating part, a variable resistance part 30 which usually enables the pass of electric energy by the energy amplifying and storing part in a low resistance state and becomes a high resistance state to generate high voltage pulses when electric energy to be stored increases, a magnetron 40 which generates electromagnetic waves when high voltage is applied, an antenna 50 that is connected to the magnetron 40 and a controlling part 60 which supplies a control signal in prescribed timing.