A direction of the first power transmission antenna is detected in a power transmission stop state from the slave power transmission apparatus after detection of a power reception apparatus, by using a master power transmission apparatus including a first power transmission device and a first power transmission antenna and a slave power transmission apparatus including a second power transmission device and a plurality of the second power transmission antennas, a second power transmission antenna in which an amount of electric power received by the power reception apparatus becomes maximum is detected in the power transmission stop state from the master power transmission apparatus, and a phase of at least one power transmission radio wave of the master power transmission apparatus and the slave power transmission apparatus is adjusted to a phase in which the amount of the electric power received by the power reception apparatus becomes maximum.