In a drying system using a compression refrigeration system, a condenser is divided into a regulating condenser and a heating condenser. The regulating condenser is capable of regulating the amount of exhaust heat discharged to outside the system. The heating condenser produces moist air by feeding heat to an aqueous object to be dried placed in a processing vessel to evaporate the moisture in the object. Heat of condensation of steam is recovered by an evaporator as heat of a refrigerant, and the recovered heat is discharged in the heating condenser to use it for the vaporization of the moisture in the object, and excess heat is discharged by the regulating condenser to outside the system.