Disclosed is an apparatus and method for wirelessly transmitting power to power receivers from a power transmitter. The present disclosure provides a rational search procedure for locations of the power receivers, and provides a function of simultaneously charging multiple receivers using microwave multi-focusing. The wireless power transmission method performed by a power transmitter includes determining angular coordinates of the power transmitter in relation to a position of at least one power receiver; determining a distance between the at least one power receiver and the power transmitter based on the determined angular coordinates by using a focused microwave field; determining a location of the at least one power receiver based on the determined angular coordinates and the distance; and wirelessly transmitting power by focusing the microwave field to the determined location of the at least one power receiver.