To provide an absorption refrigerator capable of effectively recovering an external heat source.

In this single/double effect absorption refrigerator in which an external heat source low-temperature regenerator 11, a low-temperature regenerator 3 and a condenser 5 are incorporated in one can barrel, the external heat source low-temperature regenerator 11 is disposed at an upper section of the low-temperature regenerator 3, at least a part of a diluted solution from an absorber 1 is guided to the external heat source low-temperature regenerator 11 through a low-temperature solution heat exchanger 8 and an external heat source heat exchanger 10, and then guided to the low-temperature regenerator 3, the external heat source low-temperature regenerator 11 and the low-temperature regenerator 3 have heat transfer tubes in which heating sources pass, and the solution from a solution spraying device 26 of an upper section of the external heat source low-temperature regenerator 11 is sprayed to form a liquid film on outer surfaces of the heat transfer tubes, the external heat source heat exchanger 10 is constituted by disposing the heat transfer tube on a liquid phase section of the upper section of the solution spraying device 26, and guiding the external heat source 13 to the inside of the heat transfer tube to exchange heat with the solution sprayed to the external heat source low-temperature regenerator 11, and the external heat source 13 is constituted to be guided from the heat transfer tube of the external heat source low-temperature regenerator 11 to the heat transfer tube of the external heat source heat exchanger 10.