High-pressure vessel

A high-pressure vessel comprising:

• a body portion formed in a cylindrical shape, with at least one end portion of the body portion, in an axial direction thereof, being open;
• a cap with a central protruding portion at a center of the cap, at least part of is the cap being inserted inside at least one open end portion of the body portion to plug the at least one open end portion;
• a first reinforcement layer provided on an outer peripheral surface of the body portion and made of fiber-reinforced plastic, the fiber-reinforced plastic having a first extending direction of internal fibers that coincides with a circumferential direction of the body portion;
• and
• a second reinforcement layer integrated with the first reinforcement layer and made of fiber-reinforced plastic including fibers that bridge one end portion and another end portion, in the axial direction, of the body portion, wherein
• plural protruding portions, spaced apart from each other along the circumferential direction of the body portion, are provided on an outer peripheral surface of an axial direction outer end portion of the cap, each of the protruding portions configured with at least one guide surface on a side surface of the protruding portion, and
• the fibers of the second reinforcement layer are disposed between the plural protruding portions in the axial direction of the body portion, the fibers of the second reinforcement layer abut on the guide surface and extend from between a first pair of the protruding portions toward and around the central protruding portion to abut around a portion of the central protruding portion and extend to between a second pair of the protruding portions that is substantially ninety degrees from the first pair of protruding portions with respect to the center of the cap, and fibers of the second reinforcement layer extending in a second extending direction parallel to the axial direction of the body portion, as seen in a direction orthogonal to the axial direction of the body portion.