A reed switch includes an envelope. First and second fixed terminal pieces are at one end of the envelope. A third fixed terminal piece is at another end of the envelope. A movable reed piece has a base end portion facing the one end portion of the third fixed terminal piece across a magnetic gap, a distal end portion to contact the first fixed terminal piece, and a movable contact portion. A first spring member has a base end portion secured to the first fixed terminal piece and a distal end portion to contact the movable contact portion. A second spring member has a base end portion secured to the second fixed terminal piece and a distal end portion to contact the movable contact portion. A third spring member has one and another end portions respectively secured to the movable reed piece and the third fixed terminal piece.