A blower that can reduce noise and enhance efficiency by improving a blade structure of the blower used for, for example, an outdoor equipment of an air conditioner. An impeller includes plural blades attached to a peripheral surface of a boss at intervals in a peripheral direction, and a trailing edge of the blade has a protrusion-shaped part in which its central part in a radial direction is curved to expand to a suction side. With such a structure, a discharge velocity of air can be made uniform along the radial direction of the blade, and it becomes possible to reduce noise and to enhance efficiency.