A turbo fan includes a hub for coupling a rotating shaft of a motor, a shroud, and a plurality of blades. Each blade includes an inner insertion portion disposed between the hub and the shroud, and an outer extension portion extending from the inner insertion portion and protruding beyond an outer circumference of the hub. Each blade has a positive pressure surface that includes a front surface facing toward a rotational direction and has a convex shape, and a negative pressure surface that includes a rear surface facing toward an opposite direction to the rotational direction and has a concave shape. Each blade further includes a first flow guide protrusion protruding from the positive pressure surface and arranged at an outer end of the outer extension portion, and extends from one side to the other side of the outer end of the outer extension portion in an axial direction.