A switch has a supporting terminal assembled to a base, a movable contact piece, made of a band-shaped conductive material bent to a substantially J-shaped cross section, having a movable contact at one end and having an intermediate portion rotatably supported by a rotation receiving portion of the supporting terminal, a plunger accommodated so as to be movable up and down in an internal space formed by fitting a housing to the base, and a coil spring including a forced dissociation bent portion at one end and being rotatably supported by the plunger. The plunger is moved up and down to slidably move one end of the coil spring while pressure contacting the other end edge of the movable contact piece to invert the movable contact piece and contact or separate the movable contact to and from a fixed contact, and to lock a distal end of the forced dissociation bent portion to the other end edge of the movable contact piece and exert a shear force on the movable contact of the movable contact piece.