NOVELTY - The device (2) has a power receiving inductor (21) wirelessly receiving electric power from a power transmitting device (1) through mutual inductance. A capacitor unit (24) is connected to the power receiving inductor. A rectifier (25) converts received AC power through the capacitor unit into DC power. The power receiving inductor includes a magnetic core, a coil winding and a conductor plate. The magnetic core is provided with a detachable unit (20) that is detachably attached to a housing of the power receiving device. A sensor unit (13, 28) is provided at outer side of the detachable unit.    USE - Power receiving device for supplying transmitted power to a load i.e. rechargeable battery, of an electric apparatus such as mobile terminal and an electric vehicle (claimed).    ADVANTAGE - The device is simple in structure. The detachable unit is detached from the power receiving device, so that an electric apparatus in which the power receiving device is provided as lighter in weight. The power receiving inductor is placed in the detachable unit that generates heat at time of power transmission, so that a heat dissipation structure is attached to a lid of the housing to dissipate heat via the heat dissipation structure of the electric apparatus so as to improve heat dissipation properties. The device provides two connectors to be arranged between the transmission-side detachable unit and the power transmitting device to connect the power transmitting inductor to a power source unit to avoid need to prepare a connecting unit for the sensor unit, thus simplifying structure of the power receiving device.    DETAILED DESCRIPTION - The detachable unit is a transmission-side detachable unit. The sensor unit is a RFID. INDEPENDENT CLAIMS are also included for the following:    (1) an electric vehicle    (2) a power transmitting device.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of a wireless power transmission system.    Power transmitting device (1)    Power receiving device (2)    Sensor unit (13, 28)    Detachable unit (20)    Power receiving inductor (21)    Capacitor unit (24)    Rectifier (25)