Tank made of resin

A tank made of resin, wherein a tubular projection projecting to an inside and an outside of a tank wall surface of a tank body that has a barrier layer is provided at the tank wall surface, the barrier layer is provided on an inner surface of the tank body, and an end edge of the barrier layer is molded integrally with an outer peripheral resin part of the tubular projection,

• wherein a securing part to and from which a gas-liquid separation chamber is able to be attached and detached is provided at the tubular projection, and
• the securing part has an attachment base that is larger than a width of a hole of the barrier layer,
• the outer peripheral resin part is provided at a tank-side base of the tubular projection,
• the outer peripheral resin part is formed such that a thickness of the outer peripheral resin part in a thickness direction of the tank wall surface, which is in an axial direction of the tubular projection, increases toward a longitudinal axis of the tubular projection and the outer peripheral resin part includes a portion expanding to the outside and a portion expanding to the inside,
• an end edge of the hole of the barrier layer is disposed inside the outer peripheral resin part,
• the end edge of the hole is supported by being sandwiched between the portion expanding to the outside and the portion expanding to the inside,
• a notch that is larger than the width of the hole is formed in the attachment base at a portion facing the tubular projection, and the attachment base is provided to cover the portion expanding to the inside from the inside of the tank wall surface.