There is provided a tissue elasticity measurement device 100 and a measurement method that allow for quantitative evaluation of biological changes related to tissue elasticity such as liver fibrosis. The tissue elasticity measurement device 100 has a supersonic wave measuring instrument 100a that measures a pulse waveform corresponding to a blood flow velocity by a pulse wave Doppler method, and an information processor 100b that calculates a deviation index value corresponding to a coefficient of variation from a pulse waveform obtained by the supersonic wave measuring instrument 100a.