A multiplexer including a housing including an antenna connector coupled to an antenna and a plurality of input and output connectors configured to receive or output a signal transmitted or received via the antenna according to a predetermined frequency band; a plurality of band pass filter units included in the housing and configured to pass a signal of a predetermined frequency band between the antenna connector and the plurality of input and output connectors; and a coupling unit including a plurality of feeding units to couple the antenna connector and the plurality of band pass filter units with one another.