PURPOSE: To provide an absorption type cold/hot water machine which selects the optimum operation unit based on accumulated time of the operation and shutdown, efficiency, and economical performance of each unit of an absorption type refrigerating machine equipped with a plurality of absorption type cold and hot water unit.

CONSTITUTION: The refrigeration capacity and holding water quantity of each absorption type cold/hot water unit is input into an operation control device. Based on the input values, the temperature of cold water after a specified time elapsed is predicted and each cold/hot water unit is operated in such a fashion that the temperature of cold/hot water may be constant after fixed time. This construction makes is possible to obtain an absorption type cold water/hot water machine capable of selecting the optimum operation unit from the accumulated time of operation and shutdown, efficiency, and economical performance of each unit.