Intake system

An intake system has an intake pipe (20), a passage member (40) which is inserted into a peripheral wall (24) of the intake pipe (20) in a radial direction to form an intake passage (48, 26) passing across a front end (44) and a rear end (46) thereof in a direction of insertion along with the intake pipe (20) a seal member (62) which is arranged at a seam between the peripheral wall (24) of the intake pipe (20) and the passage member (40) and seals the seam, and an elastic member (64) which is made of the same material as that of the seal member (62) integrally and is interposed between the peripheral wall (24) of the intake pipe (20) and the front end (44) of the passage member (40) so as to be capable of giving the front end (44) of the passage member (40) an elastic reaction force in a direction perpendicular to the axis of the direction of insertion.