An ultrasonic diagnostic apparatus is disclosed for transmitting ultrasonic waves and receiving echo signals. The apparatus includes an ultrasonic probe having transducers whose sensitivity can be controlled in accordance with bias voltage. Echo signals output from the ultrasonic probe are amplified so that an image can be constructed according to the amplified echo signals and displayed. A probe gain control device is used for controlling the bias voltage in accordance with the elapsed time from receiving the echo and matching the intensity of the echo signal output from the ultrasonic probe with the input range of a preamplifier. During a reception period while a strong echo signal is received from a superficial portion of body surface of an examinee, the reception sensitivity of the ultrasonic probe is controlled so that the echo signal level input to the preamplifier will not exceed the input range of the preamplifier.
