TRANSMITTER, RECEIVER, NON-CONTACT POWER TRANSMISSION CONTROL METHOD, AND COMPUTER-READABLE RECORDING MEDIUM

A power transmitting device includes a power transmitter (21) transmitting electric power in a contactless manner, a data communicator (22) obtaining identification information of at least one power receiving device that has become possible to receive electric power transmitted from the power transmitter (21), a power receiving device finding/separation detector (261) counting a number of state switchings between a power unreceivable state and the power receivable state during a predetermined period of time, for each power receiving device of which identification information has been obtained, and a power transmission controller (263) controlling electric power transmission performed by the power transmitter (21), on the basis of the number of state switchings counted by the power receiving device finding/separation detector (261).