A method of manufacturing a centrifugal fan having a main plate, a shroud, and a plurality of blades, wherein each of the plurality of blades comprises: a region defining a positive pressure surface; and a region defining a negative pressure surface; the method comprising the steps of: (a) for each blade, cutting a metal sheet to independently form a positive pressure surface forming member and a negative pressure surface forming member respectively configuring a positive pressure surface and a negative pressure surface, the positive pressure surface forming member configuring the entire region of the positive pressure surface and the negative pressure surface forming member configuring the mr entire region of the negative pressure surface; (b) pressing each of the positive pressure surface forming member and the negative pressure surface forming member to form a first curved surface portion configuring the positive pressure surface and a second curved surface portion configuring the negative pressure surface; (c) trimming the positive pressure surface forming member provided with the first curved surface portion and the negative pressure surface forming member provided with the second curved surface portion to form a shroud bonding surface portion (143, 153) and a main plate bonding surface portion (144, 154) on each of the positive pressure surface forming member and the negative pressure surface forming member; (d) bending the shroud bonding surface portion (143, 153) and the main plate bonding surface portion (144, 154); (e) bonding the positive pressure surface forming member and the negative pressure surface forming member to each other to form a blade; and (f) bonding the shroud bonding surface portion (143, 153) and a shroud to each other and bonding the main plate bonding surface portion (144, 154) and a main plate to each other in a bonded state of the positive pressure surface forming member and the negative pressure surface forming member. a region defining a positive pressure surface; and a region defining a negative pressure surface; the method comprising the steps of: (a) for each blade, cutting a metal sheet to independently form a positive pressure surface forming member and a negative pressure surface forming member respectively configuring a positive pressure surface and a negative pressure surface, the positive pressure surface forming member configuring the entire region of the positive pressure surface and the negative pressure surface forming member configuring the mr entire region of the negative pressure surface; (b) pressing each of the positive pressure surface forming member and the negative pressure surface forming member to form a first curved surface portion configuring the positive pressure surface and a second curved surface portion configuring the negative pressure surface; (c) trimming the positive pressure surface forming member provided with the first curved surface portion and the negative pressure surface forming member provided with the second curved surface portion to form a shroud bonding surface portion (143, 153) and a main plate bonding surface portion (144, 154) on each of the positive pressure surface forming member and the negative pressure surface forming member; (d) bending the shroud bonding surface portion (143, 153) and the main plate bonding surface portion (144, 154); (e) bonding the positive pressure surface forming member and the negative pressure surface forming member to each other to form a blade; and (f) bonding the shroud bonding surface portion (143, 153) and a shroud to each other and bonding the main plate bonding surface portion (144, 154) and a main plate to each other in a bonded state of the positive pressure surface forming member and the negative pressure surface forming member. (a) for each blade, cutting a metal sheet to independently form a positive pressure surface forming member and a negative pressure surface forming member respectively configuring a positive pressure surface and a negative pressure surface, the positive pressure surface forming member configuring the entire region of the positive pressure surface and the negative pressure surface forming member configuring the mr entire region of the negative pressure surface; (b) pressing each of the positive pressure surface forming member and the negative pressure surface forming member to form a first curved surface portion configuring the positive pressure surface and a second curved surface portion configuring the negative pressure surface; (c) trimming the positive pressure surface forming member provided with the first curved surface portion and the negative pressure surface forming member provided with the second curved surface portion to form a shroud bonding surface portion (143, 153) and a main plate bonding surface portion (144, 154) on each of the positive pressure surface forming member and the negative pressure surface forming member; (d) bending the shroud bonding surface portion (143, 153) and the main plate bonding surface portion (144, 154); (e) bonding the positive pressure surface forming member and the negative pressure surface forming member to each other to form a blade; and (f) bonding the shroud bonding surface portion (143, 153) and a shroud to each other and bonding the main plate bonding surface portion (144, 154) and a main plate to each other in a bonded state of the positive pressure surface forming member and the negative pressure surface forming member.