<p>An intake manifold (10) comprising a main pipe (20) made of wrought aluminum material and having an open end, a closed end opposite to the open end, a plurality of holes (21) formed in its peripheral wall and outward tubular projections (22) integral with the peripheral wall and each formed around each of the holes, and a plurality of branch pipes (30) made of wrought aluminum material and each having one end fitting in and joined to each of the tubular projections. The manifold is smooth-surfaced in its interior, diminished in resistance to air and improved in air intake efficiency. The manifold requires no finishing procedure unlike those prepared by casting. <IMAGE></p>