The present invention relates to an apparatus and method for communication service, through which a mobile station in a service area shared by a predetermined public and private mobile network is capable of getting public mobile communication network service together with private wire and mobile communication network service, the apparatus including: a base station transceiver subsystem located in the predetermined service area for providing a mobile channel with a mobile station in the service area; a communication path provider, which is connected to at least one of the base station transceiver subsystem, a base station controller of public mobile communication network, a private switch, and wire public network, for providing a communication path to be able to transmit data of the base station transceiver subsystem; a call manager, which analyzes messages that are received through the communication path provider, sorts out public mobile communication network service and private wire and mobile communication network service, and manages corresponding service calls; and a gateway, which is connected to the call manager through local area communication network, and based on signal information exchange with the call manager through the local area communication network, matches with wire communication network including the communication path provider, the private switch, and wire public communication network to transmit voice data for use of public mobile communication network service and private wire and mobile communication network service.