A pedal for a bicycle is disclosed. The pedal for a bicycle comprises a case which can rotate about a spindle; a top plate which is connected to the case by a pivot shaft and can rotate about the pivot shaft; a displacement generating assembly which is disposed in the case and is connected to the case and the top plate so as to generate displacement according to the rotation of the top plate; and a sensing unit which is connected to the displacement generating assembly so as to sense the displacement.