Intake device for a multi-cylinder engine

An intake manifold 1 for a multicylinder engine includes a collector portion 3 extending in a front-rear direction, an intake air introducing portion 4 disposed at a center in the front-rear direction of the collector portion 3, and branch portions 7, 7 led out from front and rear end portions 5 and 6 of the collector portion 3, the branch portions 7 are connected to an intake port of a cylinder head, a throttle body 8 is disposed at an upper portion of the intake air introducing portion 4, the throttle body 8 has a butterfly-type throttle valve 9, a valve shaft 10 of the throttle valve 9 is oriented in the front-rear direction, a blow-by gas inlet portion 2 is provided to the intake air introducing portion 4 of the intake manifold 1, and the blow-by gas inlet portion 2 is disposed on a side to which a lower end portion 9a of the half-open throttle valve 9 is directed and on a downstream side of the lower end portion 9a of the throttle valve 9. Thus equalization of distribution of blow-by gas into the cylinders can be facilitated.