To provide an absorption heat pump including a generator (2) or a desorber which generates vapor from a first fluid fed to a first condenser (4).

In the heat pump, an evaporator (7) is provided at a downstream side of the condenser, an outlet (7B) of the evaporator is connected by a third line (8) to an inlet of a mixer of a low-pressure absorber (100) connected to a suction side of a pump (14) feeding a solution to the generator, and the generator includes a poor solution outlet (2C) connected by a sixth line (19) provided with at least one lamination valve (30, 31) to an inlet of a poor solution fed to the absorber (100, 200-100). The second line (6) is brought into contact with the low-pressure absorber (100) to exchange heat therewith, and opens into a separator (51) of liquid and vapor fed to the evaporator (7) via a third line (6A), and an vapor outlet of the separator (51) opens into an intermediate-pressure absorber unit (200).