COMPONENT MOUNTING STRUCTURE FOR FUEL TANK

To provide a component mounting structure for a fuel tank capable of suppressing an increase in the weight of the tank body and reducing the weight and thickness of the fuel tank component, the component mounting structure includes: a tank body (2) provided with an oblong opening (2a); a pump module (3) serving as a tank component mounted to the tank body (2); a flange (5) that is provided to the pump module (3) so as to project out from an outer surface of the pump module (3), has an oblong contour larger than the opening (2a) and having a minor dimension (W2) smaller than a major dimension (L1) of the opening (2a), and is placed inside the tank body (2) through the opening (2a) with an edge thereof opposing the tank body (2) over an entire circumference; a sealing member (7) placed between the tank body (2) and the flange (5); and a fastening member (8b*9, 11*12) that holds the pump module (3) to the tank body (2) while compressing the sealing member (7) via the flange (5).