A cordless slave apparatus is connected to a host apparatus connected to lines via wireless communications. When the cordless slave apparatus is picked up from a charging apparatus to respond to a call from any of the lines, if the line at which the call has arrived has been selected by the cordless slave apparatus, the line is connected immediately and communications can start. If the line is not selected by the cordless slave apparatus, when a connection instruction from the user is provided, the line is connected and communications can start. When calls have arrived from lines simultaneously, communications can start by capturing a line according to a connection instruction. When a call from another line has arrived during communications, the lines are switched according to a switching instruction from the user and the line through which the communications have been performed is automatically turned to be on hold.