A fuel supply device mounted on an automotive vehicle includes a fuel pump and a sub-tank containing the fuel pump therein. The sub-tank and the fuel pump are submerged in fuel contained in a fuel tank. Operation of the fuel pump is controlled in a switching manner thereby to supply the fuel contained in the fuel tank to an internal combustion engine. When the fuel tank is made of a resin material, electromagnetic noises generated in the switching operation of the fuel pump are emitted from the fuel pump through the fuel tank, interfering with radio waves received by a receiver mounted on an automotive vehicle. To shield such noises, the fuel pump is disposed in the sub-tank that is made of a metallic material and grounded to a body of the vehicle. In this manner, the noises from the fuel pump are surely intercepted.