A sphygmomanometer includes an expandable/contractable air bag supplied with air a bag-shaped cover body for accommodating the air bag and for attaching the air bag to a site to be measured an expansion and contraction mechanism for expanding and contracting the air bag and a power supply unit arranged in the bag-shaped cover body. The power supply unit includes a battery for supplying driving power to the expansion and contraction mechanism, and a non-contact power reception unit for receiving power for charging the battery. The non-contact power reception unit is supplied with power through an electromagnetic inductive action from a non-contact power transmission unit arranged in a non-contact state with the non-contact power reception unit.