PURPOSE: To prevent the useless consumption of cooling water in the forced cooling of brakes and improve cooling effect.

CONSTITUTION: A brake cooling device is provided with cooling water spring means 2, 9-12 for spraying cooling water to brakes 13, 14 brake temperature detecting means 15, 16 for detecting the temperature of brakes 13, 14, and a control means 18 for operating the cooling water spray means to spray cooling water when the detected value of the brake temperature becomes the specified temperature or higher and controlling the operation of the cooling water spray means so as to increase the spray quantity of cooling water according to the increase of deviation between the detected temperature and target temperature.