A beam transmission/reception method, which is executed in a wireless communication system in which a terminal and a base station use a beam to communicate to and from each other, the beam transmission/reception method comprising a first step of controlling, by a controller of the base station which is the handover destination and can find out the timing of a random access channel signal transmitted as a connection request from the terminal in advance, when the base station is to receive the random access channel signal, a beam direction of an antenna unit by combining a plurality of beam directions by combining a main beam direction for reception of the random access channel signal indicated by a current communication partner base station of the terminal based on results of measuring broadcast signals by the terminal, with one or more beam directions adjacent to the main beam direction pertaining to a same group of a plurality of groups as the main beam direction, where the plurality of groups are the result of dividing the entirety of a service area of the base station into a plurality of beam groups, and where the first step further comprises a step of receiving, by a transmitter/receiver of the base station via the antenna unit, the random access channel signal transmitted from the terminal with use of the divided plurality of groups; and detecting, by a detector of the base station, whether the random access channel signal has been received by the transmitter/receiver, wherein the first step includes grouping beam directions, when dividing into the plurality of groups, by combining a plurality of beam directions adjacent to one another in directions of edges of the service area, as at least one of the plurality of groups. the beam transmission/reception method comprising a first step of controlling, by a controller of the base station which is the handover destination and can find out the timing of a random access channel signal transmitted as a connection request from the terminal in advance, when the base station is to receive the random access channel signal, a beam direction of an antenna unit by combining a plurality of beam directions by combining a main beam direction for reception of the random access channel signal indicated by a current communication partner base station of the terminal based on results of measuring broadcast signals by the terminal, with one or more beam directions adjacent to the main beam direction pertaining to a same group of a plurality of groups as the main beam direction, where the plurality of groups are the result of dividing the entirety of a service area of the base station into a plurality of beam groups, and where the first step further comprises a step of receiving, by a transmitter/receiver of the base station via the antenna unit, the random access channel signal transmitted from the terminal with use of the divided plurality of groups; and detecting, by a detector of the base station, whether the random access channel signal has been received by the transmitter/receiver, wherein the first step includes grouping beam directions, when dividing into the plurality of groups, by combining a plurality of beam directions adjacent to one another in directions of edges of the service area, as at least one of the plurality of groups.