AIR INTAKE DUCT

There is provided an air intake duct capable of fully achieving intake-air noise attenuation effect. The air intake duct has a duct wall section formed of resin in form of tube and configured to introduce external air into an internal combustion engine or alternate power supply system. The duct wall section is provided with a silencing member formed of a lamination of a surface layer formed of a non-woven fabric to which thermosetting resin is impregnated and a ventilation adjusting layer formed of an extendable paper material having a surface in which a plurality of concave and convex portions are formed, and the silencing member includes at least one pair of the surface layers on front and back surfaces of at least one pair of the ventilation adjusting layers, and an intermediate layer is formed between the paired ventilation adjusting layers, the intermediate layer being formed of a same material as that of the surface layer.