A shell is constituted by an outer shell and an end plate. The end plate has a port in communication with a liquid chamber. A bladder divides an internal space of the shell into a liquid chamber and a gas chamber. A gas is introduced into the gas chamber without the provision of a gas inlet hole in the outer shell located on the side of the gas chamber. For example, an accumulator is assembled by combining the outer shell, the end plate and bladder under atmosphere of a high pressure gas.