A sphygmomanometer according to the present invention includes a main body mounted with a pump, a belt, and a cuff structure. The cuff structure having a band shape is disposed facing an inner circumferential surface of the belt and has one end attached to the main body in a freely separable manner from the inner circumferential surface of the belt. The cuff structure includes a bag-shaped pressure cuff that extends along a circumferential direction of a measurement target site, a bag-shaped sensing cuff that extends in the circumferential direction across an artery passing portion of the measurement target site, and a back plate that is inserted between the pressure cuff and the sensing cuff. A pressurization fluid is supplied from the pump to the pressure cuff to press the measurement target site. A blood pressure is calculated based on a pressure of a pressure transmission fluid contained in the sensing cuff.
