Intake manifold

An intake manifold to be applied to an engine with a plurality of cylinders, comprising:

• a surge tank into which intake air flows;
• and
• branch pipes branched from the surge tank and connected to intake ports of the engine, wherein
• the surge tank includes an internal space formed between a first wall surface and a second wall surface facing each other,
• the first wall surface and the second wall surface are connected with a pillar portion penetrating through a substantially center portion of the internal space,
• a cross section of the pillar portion perpendicular to an extending direction of the pillar portion has an oval shape elongated in a passing direction of the intake air in the internal space, and
• a distal end portion having a distal end surface of the pillar portion abuts against a recessed portion of the first wall surface and is connected by welding,
• the recessed portion is formed by the surge tank on a side of the internal space of the first wall surface being recessed,
• the distal end surface of the pillar portion has a shape that is substantially similar to that of the cross section perpendicular to the extending direction of the pillar portion and is an elliptical shape elongated in a side of the branch pipes, and
• holes through which a bolt is insertable are formed at positions where the distal end surface of the pillar portion and the recessed portion face each other.