PURPOSE: To provide a receiver of high sensitivity for detecting an FM signal sent from a radio altimeter or the like.

CONSTITUTION: FM signal detecting equipment includes a phase detector 24 to which a reception signal 21a and a delay replica 21b of an input signal are inputted and an output of the phase detector 24 is filtered by a filter bank 26, an output of which is sent to a logic circuit 28. The logic circuit 28 selects the output having the maximum signal level. An output signal of this circuit is compared and discriminated by a threshold circuit 30, and in the case when the signal has a level higher than a prescribed threshold, the presence of an FM signal is indicated.