To provide a power consumption control method for portable telephone set with which power consumption can be reduced when an effective channel can not be retrieved.

When the effective channel can not be retrieved in perch channel retrieval, until it exceeds the set period of a timer B (step S1) predetermined for turning off a power source, a low power consumption mode state (steps S6-S8) is repeated (step S8) for the preset period of a timer A (step S5) and when it exceeds the set period of the timer B as a result of repetition, the power source of the portable telephone set is turned off by the selection by a user (steps S10, S12 and S13).