To provide a cordless telephone set which is capable of avoiding the occurrence of a communication disabled state and a method for controlling the telephone set.

A method for controlling a cordless telephone set is composed of a first stage of confirming the existing zones of one or more mobile telephone terminals 2-l to 2-L, to which specific zone information and public calling information are assigned via one or more specific zone base stations 5-1 to 5-m in the service areas of the base stations 5-1 to 5-m when a call is originated to one of the terminals 2-1 to 2-L, a second stage of confirming whether or not the call originated to one of the terminals 2-1 to 2-L is an extension call, and a third stage of confirming whether or not the public calling information corresponding to the above telephone terminal is stored in the public information storing means 4 corresponding to the telephone terminals 2-1 to 2-L.