PURPOSE: To keep the shut-off of the noise caused by damping elements without any changes for a long time by providing a structure in which the damping elements maintain their elasticity in a fuel.

CONSTITUTION: A mounting device 10 is provided with a support base comprising two elastically flexible damping elements 20, 22 so that the working noise of a fuel pump 12 is shut off from a fuel tank bottom part 14 to a degree at least not to be felt as the noise, and the damping elements are arranged in long support housings 24, 26. The pump 12 is held approximately at its intermediate part by a tubular clip 30, a side clip flange is tightened by a ski-like support member 46, and the support member 46 itself is held through the friction contact with the elements 20, 22 by a pair of holding clamps 52, 54. The elements 20, 22 consist of a plastic not to be expanded or solidified in the fuel, and is formed of a non-woven fabric to guarantee the desired noise shut-off as a result of its elasticity. At the same time, two non-woven fabrics are packed in the support housings 24, 26 in a relatively dense manner.