Abstract: An industrial robot having a dust-proof structure is equipped with at least one dust cover having an opening at one end thereof and a linearly movable unit extending through the opening of the dust cover and movable back and forth in the longitudinal direction thereof. Suction is exerted by a suction unit inside the dust cover so that air is flows from outside the dust cover into the same through the opening. A ring member is disposed at the opening of the dust cover in such a manner as to encompass the outer periphery of the linearly moving unit through a gap. At least one annular groove for reserving air is disposed on the inner peripheral surface of the ring member so as to encompass the outer periphery of the linearly moving unit.