A handler includes a storage tank which stores liquid nitrogen, supply channels which supply refrigerant from the storage tank to inner passages of a first shuttle, a valve which opens and closes the supply channel, and a heat exchanger which has vaporization chambers with larger flow path cross-sectional areas than those of the supply channels to vaporize liquid nitrogen within the vaporization chambers. According to this structure, the respective vaporization chambers are filled with nitrogen gas produced by preceding vaporization. Thus, pressure fluctuations produced by successive vaporization of liquid nitrogen can be reduced. Moreover, nitrogen gas is supplied to the respective inner passages. Accordingly, excessive cooling for part housing pockets can be prevented.