Abstract: A multi-cavity klystron device having a plurality of resonance cavities, comprising a plurality of movable elements, each of which is mounted on each of said resonance cavities and which is adapted to change the resonance frequency in each cavity, a plurality of tuning means for giving a reciprocal movement to each movable element against a resilient member provided therefor, a plurality of pulse motors coupled to the tuning means, and a preset means for controlling pulse supply to each pulse motor, wherein a predetermined number of pulses stored in the memory units of the preset means are selectively applied to the pulse motors to rotate each pulse motor in correspondence with the number of pulses, thereby changing each resonance frequency of each cavity.