A headrest device ensures the movement of a headrest frame body to a stay and enables a foaming resin molding of a headrest. A support portion having a semicircular cross section and restricting portions having an approximately U-shape cross section are formed on a plate body. Two sheets of plate bodies are connected with each other in an opposed manner. Then, a headrest pad made of foaming resin is integrally formed with the plate bodies. <IMAGE> <IMAGE>