To discharge dust to the outside of a shroud by cleaning a cooling core without opening the shroud and a grill in a liquid cooling device such as a radiator and an oil cooler.

This liquid cooling device 10 comprises the cooling core 21 for the cooling water of an engine in which a large number of water flow tubes for flowing the cooling water of the engine therein are disposed and a cooling core 32 for the hydraulic oil of a hydraulic device in which a large number of oil flow tubes for flowing the hydraulic oil of the hydraulic device therein are disposed. Also, the liquid cooling device 10 comprises a cooling fan 13 circulating the air around the water flow tubes of the cooling fan 21 and around the oil flow tubes of the cooling core 31 and the shroud 14 covering the cooling core 21 and the cooling core 31. The shroud 14 comprises a cleaning hole 51 for discharging dust 95 in the shroud 14. For example, when compressed air 91 is blown against the cooling core 21 from the outside of the shroud 14, the dust 95 entrapped in the cooling core 21 and the cooling core 31 is blown off, and discharged from the cleaning hole 51 to the outside of the shroud 14.