A server includes: a communicator configured to communicate with a plurality of ground power supply devices configured to transmit electric power to a vehicle in a non-contact manner; a storage configured to store at least information on a total power supply amount within a predetermined period of the ground power supply devices; and one or more processors configured to, when a total power supply amount within a predetermined period of one ground power supply device among the ground power supply devices is equal to or greater than a determination threshold value set based on data of the total power supply amount within the predetermined period of the ground power supply devices, determine that stealing or leakage of electricity has occurred in the one ground power supply device.