There is provided a spindle motor including: a lower thrust member fixedly installed on a base member and including an extension part extended upwardly in an axial direction; a shaft having a lower end portion fixedly installed on the lower thrust member; a sleeve rotatably installed with respect to the shaft; an upper thrust member fixedly installed on the shaft to correspond to an upper portion of the sleeve; and a rotor hub rotating together with the sleeve, wherein an end portion of the extension part and a surface of the sleeve opposed thereto are provided with rounded surfaces.