A control method includes obtaining information indicating an amount of charge of at least one first electric vehicle that is connected to a power system and that is capable of receiving transmission power via a first system facility, obtaining information indicating a first threshold set for the amount of charge of the at least one first electric vehicle, and controlling, when the transmission power via the first system facility exceeds an upper limit smaller than or equal to a power capacity of the first system facility, charging or discharging of the at least one first electric vehicle on a basis of a comparison between the amount of charge of the at least one first electric vehicle and the first threshold in such a way as to reduce the transmission power via the first system facility.