A control method for a power transmitter, a power transmitter and a noncontact power transfer apparatus are disclosed. An inverter in the power transmitter is controlled to be intermittently input a voltage in the standby mode, and the input voltage of the inverter is controlled to show a gradually increasing or gradually decreasing trend when there is a voltage value input in the standby state. According to the control method for the power transmitter, the power transmitter and the noncontact power transfer apparatus of the present disclosure, it can achieve smooth transition from the standby state to the normal state, and the standby efficiency and the normal operation efficiency can both be improved.