A switch for a rotating machine is provided with: a casing supporting two or more terminals respectively having contacts so as to hold the contacts exposed on an inside of the casing; a rod having a rod body fitting in the casing axially movably from a first position to a second position; a first spring axially biasing the rod returning back; a carrier housed in the casing and combined with the rod body to follow axial motion of the rod body; a conductor carried by the carrier and exposed on a side face of the carrier toward the terminals and depart from the terminals at the second position; a second spring intervening between the carrier and the conductor to bias the conductor toward the contacts; and a seal intervening between the rod and the casing and fluid-tightly isolating an interior of the casing.