Intake system for internal combustion engine

An intake manifold of an engine has a common pipe disposed downstream of a throttle valve, a plurality of first through fourth branch pipes connected to the common pipe, and a bypass pipe connected between the common pipe and the first through fourth branch pipes. The bypass pipe has a plurality of branches connected respectively to the first through fourth branch pipes. An amount of intake air flowing through the intake manifold is detected by an air flow meter disposed in the bypass pipe.