PROBLEM TO BE SOLVED: To improve elasticity measuring accuracy in ultrasonic diagnostic equipment.SOLUTION: Based on a plurality of frames generated by the scanning of an ultrasonic beam, a time change in a displacement amount of a biological tissue is calculated and a displacement waveform indicating the time change in the displacement amount is generated. This displacement waveform is attributed to a breathing movement of a subject, for example. Based on the result of analysis of the displacement waveform, an instruction for breathing and breath-holding is issued. When an instruction for breathing is repeated and periodicity of the displacement waveform is detected, an instruction for breath-holding is issued. For example, when a B point in the displacement waveform (a point when the displacement amount becomes maximum when the subject is breathing) is detected, an instruction for causing the subject to breathe out is issued. Then, a C point (a point when the displacement amount (absolute value) becomes maximum when the subject is breathing out) is detected, an instruction for breath-holding is issued. After the instruction for breath-holding, elasticity measurement is performed according to the displacement amount.SELECTED DRAWING: Figure 3
