Abstract: A camshaft for internal combustion engines, the camshaft having a double-pipe shaft portion comprising an outer pipe, an inner pipe, and an intermediate layer therebetween. The intermediate layer is composed of a layer of a thermoplastic liquid crystalline polyester resin that has been injected into a gap between the outer pipe and the inner pipe, by an injection molding machine. The camshaft is lightweight and has excellent vibration-damping properties, and further, has a structure allowing an easy manufacture thereof, and thus is suitable for mass production.