To obtain an air conditioner having a lower-noise centrifugal fan capable of improving product reliability during transportation and execution properties of installation, with reduced packaging materials in favor of environment. The shape of a blade is formed so that when a blade edge positioned on the downstream side of the blowing direction is designated as a blade rear-edge, the centrifugal fan has a relationship of the outer diameter of the side plate>the outer diameter of the blade rear-edge on the side of a side plate>the outer diameter of the blade rear-edge on the side of a main plate≧the outer diameter of the main plate, and the blade rear-edge is located inside of a straight line connecting a connection point between the blade rear-edge and the main plate to a connection point between the blade rear-edge and the side plate relative to the rotation axis of the fan, and the distance between the blade rear edge and the rotation axis increases toward the side plate from the main plate.