An ultrasonic oscillation device adapted for use in surgical operations includes, for the purpose of producing ultrasonic vibrations of an amplitude and power capable of exhibiting a satisfactory tissue shattering capacity in a wide field of living tissues, an ultrasonic oscillation section having a power amplifier circuit for adjusting the amplitude of its output without any difference in phase between the output and a feedback signal, and a starting impulse reducing circuit for reducing the impulse due to a transient current upon the starting of oscillation. Also, an ultrasonic transducer includes an electrostriction type transducer and a horn, and the horn forming a scalpel portion is provided with a suction opening adapted for irrigating an affected part operated on and its surrounding, floating shattered cellular pieces and sucking and removing the floating cellular pieces.