Provided is a turbo fan. The turbo fan includes a main plate rotating by a fan motor providing power and a plurality of blades having one ends connected to the main plate, the plurality of blades being disposed along a circumferential direction on the main plate. Each of the plurality of blades includes a first curved part curved in one direction with respect to an extension part and a second curved part curved in the other direction with respect to the extension part. A plurality of projections protruding in one direction from the one end of the blade and a plurality of grooves protruding in the other direction are alternately disposed on the first and second curved parts. Alternatively, the turbo fan includes a main plate rotating by a fan motor providing power, a rotation shaft providing a rotation center of the main plate, a plurality of blades having a blade front end disposed adjacent to the rotation shaft and a blade rear end disposed spaced from the rotation shaft, the plurality of blades being disposed in a circumferential direction on the main plate, and an extension part defined as a virtual line straightly extending from an upper portion of the blade rear end to a lower portion of the blade rear end. Each of the blades includes a first curved part curved in one direction with respect to the extension part, a second curved part curved in the other direction with respect to the extension part, a first flow part defined as a space between the extension part and the first curved part, and a second flow part defined as a space between the extension part and the second curved part.