A radio tuner for diversity reception, wherein a fixed antenna and a retractive antenna are installed as a receiving antenna and whichever the antenna at the stronger electric field strength is selectively switched to receive a radio signal in response to the received electric field strength, and thereby the receiving antenna system is selected compulsively to be the fixed antenna at the time when the retractive antenna is being protracted or retracted by monitoring a driving state of the retractive antenna. Thus, the receiving antenna system is never changed to the retractive antenna in the diversity reception as long as the retractive antenna is moving for protraction or retraction and a noise accompanying the protraction or retraction of the retractive antenna is prevented from entering into the received radio signal.