Intake duct for internal combustion engine

An intake duct for an internal combustion engine, the intake duct comprising a tubular side wall, wherein

• the side wall includes a first molded body and a second molded body that are separate from each other in a circumferential direction of the side wall,
• the first molded body includes first and second joints respectively located on opposite ends of the first molded body in the circumferential direction,
• the second molded body includes first and second joints respectively located on opposite ends of the second molded body in the circumferential direction,
• the first and second joints of the first molded body and the first and second joints of the second molded body are joined to each other,
• the first molded body includes a rib protruding toward the second molded body and extending in an axial direction of the side wall, the rib being located inward from the first and second joints of the first molded body, and
• the second molded body includes an accommodation recess that accommodates the rib, the accommodation recess being located outward from the rib.