Any of a plurality of contact plugs which reaches a diffusion layer serving as a drain layer of an MOS transistor has an end provided in contact with a lower surface of a thin insulating film provided selectively on an interlayer insulating film. A phase change film constituted by GST to be a chalcogenide compound based phase change material is provided on the thin insulating film, and an upper electrode is provided thereon. Any of the plurality of contact plugs which reaches the diffusion layer serving as a source layer has an end connected directly to an end of a contact plug penetrating an interlayer insulating film.