A refrigerant supply apparatus for supplying a refrigerant to a cooling target. The apparatus includes a refrigerant supply channel through which pure water as the refrigerant is supplied to the cooling target, an impurity removing unit disposed in an impurity removing channel which is a channel different from the refrigerant supply channel, a sensor which measures a purity of the pure water, and a valve which stops supply of the pure water to the cooling target when the purity of the pure water does not satisfy a predetermined standard.