Provided are a film cartridge, a film unit, and a layer transfer device capable of restraining a supported layer including a transfer layer from being touched by an operator and restraining the supported layer remaining on the supporting layer remaining on a supporting layer from coming off. A film cartridge includes a supply reel on which a multilayer film including a supported layer with a transfer layer included therein and a supporting layer is wound, and a take-up reel on which to take up the multilayer film. The multilayer film is wound on a supply shaft in such a manner that the supported layer is in contact with the supply shaft, and the multilayer film is wound on the take-up shaft in such a manner that the supported layer is in contact with the take-up shaft.