An apparatus, method and medium converting a motion signal, which is capable of controlling the motion of the pointer according to a user's intention by removing noise using a filter for the detected motion signal of the pointer in accordance with the moving speed of the pointer. The apparatus includes, a motion detecting unit to detect a motion, a determining unit to determine a type of motion signal according to the detected motion, and a filter unit including at least one filter to convert the motion signal using a filter that corresponds to the type of motion signal, the filter being selected from among the at least one filter.