To select a combination of solute and solvent for stably performing refrigeration in a household scale and determine the shape and layout of each component for miniaturization in a dissolution type production method of cold and hot water comprising performing refrigeration by use of endothermic phenomenon in dissolution of a solute.

In the dissolution type cold/hot water production method, potassium thiocyanate is used as the solute, and water is used as the solvent. A crystallizer, a contact conduit, and a dissolver are successively continuously arranged downward in the vertical direction. The cold heat of a low-temperature diluted solution in the dissolver and the hot heat of a condenser and a high-temperature condensed solution are taken out and used, respectively.