A power transmitter 50 is usable in a wireless power transmission system for transmitting power wirelessly. The power transmitter 50 includes a power transmitting section 51 for transmitting power; a communication section 52 for communicating information, for controlling the transmission of the power, with the power receiver 60; and a control section 53 for controlling the power transmitting section 51 such that the power to be sent out by the power transmitting section 51 is higher while the communication section 52 is performing the communication.