A rain sensor, for motor vehicles in particular, having one measuring distance with at least one transmitter and at least one receiver for electromagnetic waves (light waves), a windshield being arranged in the measuring distance, and the measuring distance influencing the wave propagation between the at least one transmitter and the at least one receiver in such a way that when a coating forms on the windshield, in particular as the result of wetting by precipitation, an output signal sensed by the receiver is changed. It is provided that the optical and electronic components of the rain sensor are mounted in a housing, a light conducting element forming a cover of the housing.