A absorption chiller-heater includes a low temperature regenerator, a high temperature regenerator, a condenser, an evaporator, an absorber, and a heat exchanger, in which water is used as a refrigerant and a lithium bromide aqueous solution is used as an absorption liquid, and the absorption liquid contains a molybdate as a corrosion inhibitor, sodium sulfite or sodium bisulfite as a concentration improving agent, and an octyldimethylethylammonium salt or a lauryldimethylethylammonium salt as a dispersant.