A blood pressure measurement device is equipped with a pressing surface 6b which is formed with element arrays of plural pressure sensors 6a and 7a that are arranged in one direction, an air bag 2 for pressing the pressing surface 6b against a living body part including a radius artery T running in a state that the one direction crosses a direction in which the radius artery T runs, an air bag drive unit 11 for controlling a pressing force of the air bag 2, a rotational drive unit 10 for driving the pressing surface 6b rotationally about at least one of axes X and Y that are perpendicular to a pressing direction of the air bag 2, and a control unit 12 which performs a rotation control on the pressing surface 6b on the basis of pressure pulse waves that were detected by the pressure sensors 6a and 7a in a process that the pressing force was increased and calculates blood pressure values in the radius artery T on the basis of pressure pulse waves that were detected by the pressure sensors 6a and 7a after the rotation control in a process that the pressing force was decreased.