To solve the problem that a constitution of a conventional system is complicate and heavy and the system cannot be freely carried therewith.

An air conditioning system comprises a dehumidifier 2 for dehumidifying a moisture in the air, and a cold/warm heat generator 35 for generating a cold or a warm heat. The generator 35 has a water holding material 21 for carrying a hydrate salt 25, a heating means 31 for heating the holding material 21, and a temperature controller 32 for heating the hydrate salt to a state of an anhydrous salt or a dihydrate salt by the heating means, when the warm heat is generated or heating the hydrate salt to a form of a hexahydrate salt when the cold is generated or controlling a supply air amount of the supply fan 5 of the dehumidifier 2.