PURPOSE: To detect information regarding motion in a wide frequency range with high accuracy stably on the whole by buffering a large body motion detection output generated owing to a shock and correcting the output, etc., by using a body motion detection output for detecting relative motion.

CONSTITUTION: The relative motion is detected by finding the relative displacement between a lens barrel 82 as a body capable provided to a lens barrel 82, of moving spatially and an angular speed indicator as a motion detecting means by plural magnetic sensors 11a and 11b provided to the lens barrel 82 and a magnetic body put in an angular speed indicator storage case 71. Then such a problem that the motion detecting means generates the large output owing to the shock is eliminated by the buffer means composed of a buffer member 73 and a resulting problem is corrected by using the output of a relative motion detecting means which detects the relative motion between the body and motion detecting means to reduce the influence of the shock and also detect the accurate information regarding the motion.