A thin, film-form seating switch able to detect whether an occupant sits on the seat or not, wherein, with a spacer (5) in-between, a film-form substrate (3) is disposed on one surface of the spacer and a film-form member (7) on the other surface, a first conductor (13) equipped with a first terminal (9) and a first electrode (11A) conductive with this and a second conductor (19) equipped with a second terminal (15) and a second electrode (17A) conductive with this are fixed to one surface of the film-form substrate, and a third conductor (21A) for letting the first electrode conduct with the second electrode when an occupant is seated is fixed to the film-form member (7). The above arrangement solves a conventional problem that it is troublesome to connect the connection terminals of wires or the like provided on a wiring harness or the like to respective terminals that are separately provided on a film-form substrate and a film-form member.