WIRELESS POWER TRANSFER SYSTEM

A wireless power transfer system wirelessly transfers power from a supply device to a vehicle, the supply device including a primary device that transfers power and being provided on a road, the vehicle being equipped with a power reception device that includes a secondary device and traveling on the road by the power received from the supply device. Further, the supply device further includes: a processor, and the processor: acquires vehicle speed information indicating at least a speed of the vehicle; and sets a time for confirming magnetic coupling between the primary device and the secondary device based on the vehicle speed information.