The present invention provides an intake manifold that improves the intake performance and has a reduced weight. The intake manifold includes a surge tank and intake pipes. Each intake pipe has an inlet port that is connected to the surge tank. The inlet ports are arranged along a flow direction of air drawn into the surge tank from the opening of the surge tank, and project into the surge tank along direction that intersects the flow direction. Each adjacent pair of the inlet ports are separated only by a single common pipe wall.