Provided is a spindle motor having a clamping device. The spindle motor includes a bearing housing disposed on a base, a rotation shall rotatably supported by a bearing in the bearing housing, a stator coupled to the bearing housing, a bush directly coupled to the rotation shaft exposed from an upper portion of the bearing housing, a rotor yoke directly coupled to the bush, a magnet fixed on an inner circumference of the rotor yoke, and a clamping device disposed on the rotor yoke. The clamping device includes a body, a stopper, a weight, and an elastic member. The stopper is coupled to the body. The weight is coupled to the stopper. The elastic member elastically supports the stopper.