One driving device (12) includes an output voltage of decomposition unit (1221), decomposes the output voltage for being applied to a ultrasonic transducer into a basic module and a harmonic component One output electric current of decomposition unit (1222) decomposes the output electric current flowed by ultrasonic transducer into a basic module and a harmonic component One condenser current calculator (1223) calculates the basic module and a harmonic component of Cb electric currents, basic module and harmonic component based on output voltage One driving current calculator (1224), the harmonic component of one basic module of its driving current for calculating a ultrasonic transducer based on basic module and a harmonic component and the harmonic component and Cb electric currents of output electric current and basic module, one driving current summation unit (1226), its basic module and harmonic component for summarizing driving current, generation determines flow control data to control driving voltage, so that the constant-current controller (1227) that driving current is summarized has a target value.
