Ultrasonic diagnostic apparatus and probe used for same

The invention provides a ultrasonic diagnostic apparatus realizing a TGC circuit suitable for being mounted in a 2D array probe and a probe used for the same. The probe transmits an ultrasonic wave toa diagnostic site and receives a reception signal which is a reflected wave. The probe includes: a plurality of transducers; a plurality of low-noise amplifying circuits respectively corresponding tothe plurality of transducers; and a single differential converter which converts a control signal rising with the elapse of time to a first bias signal rising with the elapse of time and a second bias signal falling with the elapse of time to control the plurality of low-noise amplifying circuits, and the low-noise amplifying circuit includes: an attenuator which attenuates an electric signal from the transducer; a first amplifying circuit which sets the first bias signal as a bias and amplifies an output signal of the attenuator to be gradually increased with the elapse of time; a second amplifying circuit which sets