A moving vector calculation unit calculates a moving vector M representing a quantity and a direction of movement of a probe on basis of a stylus displacement vector, a stylus displacement vector D, and a direction change angle θ of the stylus displacement vector D that is caused by a frictional force between a stylus 32 and the measuring surface 5a during scanning of the measuring surface 5a by the stylus 32. The stylus displacement vector D is a vector including a quantity and a direction of position displacement of the stylus 32 relative to the probe 5. Movement of an XY-stage 7 is controlled so that the probe 6 moves in accordance with the moving vector M.