FUEL TANK

A fuel tank includes an internal component having a head portion, a neck portion, and a shoulder portion, in which the internal component is fixed on a tank main body by shaping a parison to the head portion, the neck portion and the shoulder portion during molding of the tank main body. Here, in the fuel tank, the head portion has a rotation-stopping shape. The rotation-stopping shape is preferably an elliptical shape or an oval shape. Further, the rotation-stopping shape is preferably a broad bean shape.