A stage driving device includes a secured section; a movable section supported movably along a movement plane relative to the secured section; a driver including a magnet at one of the secured section and the movable section and a coil at the other one of the secured section and the movable section; a magnetic sensor at one of the secured section and the movable section provided with the coil, the magnetic sensor configured to detect a position of the movable section with respect to the secured section; and a magnetic body at the one of the secured section and the movable section provided with the coil, the magnetic body configured to make the position of the movable section stable with respect to the secured section in a direction perpendicular to the movement plane using a magnetic force that acts between the magnetic body and the magnet.