A robot system of the present disclosure includes: a robot including an operable working arm; a motion speed detection unit configured to detect a motion speed of the working arm; a region setting unit that sets a region with a predetermined range around the robot; a moving body detection unit configured to detect a position of the moving body other than the robot; and an abnormality determination unit configured to determine abnormality when detecting of the position of the moving body within the region, wherein the region setting unit changes the range of the region according to the motion speed of the working arm.