PURPOSE: To suppress power consumption with respect to the power save device for an FM radio receiver using a battery for a portable telephone set as a power supply in which a reception electric field strength is fluctuated.

CONSTITUTION: This device is provided with an electric field intensity detection means 1 detecting a voltage in response to a reception electric field strength, a power variable means 3 varying a power fed to a supplied section 2 including an active element before a demodulation stage of a reception circuit and a control means 4 controlling the operation of the power variable means 3 in response to a voltage detected by the electric field strength detection means 1. The control means 4 controls the operation of the power variable means 3 in response to the voltage detected by the electric field intensity detection means 1. Thus, the power variable means 3 varies the power supplied to the supplied section 2 to reduce the power consumed by the section 2.