This disclosure provides a power transmitting apparatus including coupling electrodes couplable to a power receiving apparatus to transmit power to the receiving apparatus. A high-frequency voltage generator circuit is adapted to supply a high-frequency voltage across the coupling electrodes in accordance with a signal output from a control circuit. A driving power supply switching circuit switches between applying a constant voltage and supplying a constant current to the high-frequency voltage generator circuit. First, by sweeping the driving frequency of the high-frequency voltage generator circuit in a state in which a constant current is supplied, it is determined whether there is a maximal value in the frequency characteristics of a voltage applied to the high-frequency voltage generator circuit. When there is a maximal value, the corresponding frequency is set as the driving frequency, and power transmission is started after the driving power supply switching circuit is switched to a constant voltage.