An ultrasonograph comprising an ultrasonic probe, a transmitting unit for transmitting an ultrasonic signal to a subject through the ultrasonic probe, a receiving unit for processing the received signal received by the ultrasonic probe, and an image creating unit for creating an image from the received signal processed by the receiving unit. The transmitting unit has a function of transmitting the ultrasonic signal having a varying frequency in the same direction at temporal intervals a plurality of times. The repetitively transmitted ultrasonic signal includes a first waveform having an increasing frequency and a second waveform having a decreasing frequency. The receiving unit has a function of effecting in-phase addition of the received signal corresponding to the first waveform to thereceived signal corresponding to the second waveform. While maintaining the resolution of tissue harmonic imaging, the penetration is improved.