To provide a radiator grill device capable of shortening a warming operation time for warming the cooling water of an engine and a hydraulic fluid of a hydraulic device and preventing the excessive cooling of the cooling water and the hydraulic fluid.

The radiator grill device (14) is provided with a louver (30) mounted to a radiator opening (16) so as to be openable and closable; a drive means (32) for opening and closing the louver (30); a water temperature detection means (34) of the engine cooling water and an oil temperature detection means (36) of the hydraulic fluid; and a control means (38) for positioning the louver (30) at "a closed position" when at least one of the water temperature and the oil temperature is lower than respective set temperatures and for positioning the louver (30) at "an opened position" when both the temperatures are higher than the set temperatures.