A blood pressure measurement device is equipped with a pressing surface which is formed with pressure sensors, an air bag for pressing the pressing surface toward a radius artery that runs under a skin of a living body； an air bag drive unit for controlling the pressing force of the air bag, and a control unit for calculating blood pressure values in the radius artery on the basis of pressure pulse waves that were detected by all of the pressure sensors in a process that the pressing force was increased or decreased.
