To enable, in a centrifugal fan disposed with a resin-made impeller of the type that sucks in gas from a rotating shaft direction and blows out the gas in a direction intersecting the rotating shaft, a reduction in the weight of the impeller even when utilizing blades that extend while twisting in the shaft direction. An impeller (42) of a fan (4) includes an end plate (43), plural blades (44) and an end ring (45). The blades (44) comprise blade bodies (51) that are annularly disposed around a shaft (41a) and fixed to the end plate (43) and blade covers (61) that are attached to the blade bodies (51) and configure a hollow space (S) between themselves and the blade bodies (51). The end ring (45) is disposed such that it sandwiches the plural blades (44) between itself and the end plate (43) in the shaft direction, and is fixed to the end plate (43). The blade covers (61) are disposed such that they configure at least part of negative-pressure surfaces (44f) of the blades (44).