A centrifugal fan includes a plurality of fan blades arranged spaced apart from each other in a circumferential direction. The fan blade has an inner edge portion disposed on an inner peripheral side and an outer edge portion disposed on an outer peripheral side. The fan blade has a blade surface including a pressure surface and a suction surface. When cut along a plane orthogonal to a rotation axis of the fan, the fan blade has a blade cross section having concave portions formed at the pressure surface and the suction surface. A plurality of fan blades include fan blades having blade cross sections of different shapes. With such a configuration, the fan has an excellent air-blowing capacity while preventing noise. A molding die for use in production of the fan and a fluid feeder including the fan are also provided.