A pressure vessel includes a vessel body, a covering part, and a cylindrical mouthpiece. The vessel body includes a cylindrical open end portion on at least one end side of the vessel body. The covering part is made of a fiber reinforced resin and covers an outer surface of the vessel body. The mouthpiece is configured such that a plurality of mouthpiece bodies each having a projection on an inner surface of the mouthpiece body is connected to each other in a circumferential direction of the open end portion. The mouthpiece is attached to an outer peripheral surface of the open end portion by the projections biting into the covering part covering the outer peripheral surface of the open end portion. The mouthpiece bodies of the mouthpiece are connected to each other by fitting together fitting portions formed at end portions of the mouthpiece bodies in the circumferential direction.