A filler tube, which is capable of satisfying required functions suitably in compliance with the bellows and non-bellows cylindrical base while securing weld strength and fuel-permeation resistance property in the weld face, is provided. A filler tube includes a non-bellows cylindrical base with a total thickness of from 2 to 4 mm, a bellows with a total thickness of from 0.5 to 3 mm, and a flange having a total thickness of from 3.5 to 5 mm, and including an end face to be welded to a fuel tank. The non-bellows cylindrical base, the bellows, and the flange include inner layers formed so as to have a thickness accounting for from 40 to 60% of the total thicknesses, and formed of high-density polyethylene (or HDPE) serving as the major constituent, intermediate layers exhibiting fuel-permeation resistance property, and outer layers protecting the intermediate layers.