A centrifugal fan 1 includes a main plate 10, a shroud 20, and a plurality of blades 30 provided between the main plate 10 and the shroud 20. The blade 30 includes abutting surfaces 34, 35a, and 35b that respectively abut on abutted surfaces 12a, 22a, and another abutted surface formed on at least one of the main plate 10 and the shroud 20. The abutting surfaces 34, 35a, and 35b includes projections 36, 37a, and 37b formed thereon, respectively, and extending in a straight or curved line. The abutting surfaces 34, 35a, and 35b and the abutted surfaces 12a, 22a, and the other abutted surface are respectively welded to each other by laser beams 40 and 41 respectively directed onto and moved along the projection 36 and the projections 37a and 37b.