Cordless telephone system having power interruption detection

In a cordless telephone system having a mobile telephone set and a charging stand, the mobile telephone set includes at least one charging terminal and a charging control terminal, and control circuitry for monitoring the at least one charging terminal and the charging control terminal, and controlling whether or not the mobile telephone set is permitted to operate in a quick communication mode. The quick communication mode is a communication mode of the mobile telephone set in which the mobile telephone set automatically begins to transmit an outgoing call of the telephone system or to receive an incoming call, when the mobile telephone set is picked up from the charging stand.