To provide an intake system duct supplying outside air taken in through an intake system component for an internal combustion engine especially an air cleaner to an engine body, made of rubber composition having vibration damping effect while maintaining flexibility of rubber.

This component is made of rubber composition compounding 10 - 30 weight part of laminated crystal filler to 100 weight part of NBR. Mica is compounded as the laminated crystal filler. An intake system duct supplying outside air taken through the air cleaner to the engine body is constructed as the intake system component. Resin excellent in ozone resistance is compounded in the rubber composition. Acrylic resin is used as resin excellent in ozone resistance.