An absorption heat pump device capable of suppressing a reduction in performance as the absorption heat pump device resulting from improper control of the concentration of an absorbing liquid due to the inclination, shaking, etc. of a vehicle body at the time of mounting the absorption heat pump device on a vehicle is provided. An absorption heat pump device (100) in which an absorbing liquid absorbs refrigerant vapor includes an evaporator (30) that evaporates a refrigerant and an absorber (40) in which the refrigerant vapor evaporated in the evaporator is absorbed by the absorbing liquid. The absorber includes a heat exchange section (42) that removes absorption heat of the refrigerant vapor into the absorbing liquid and a membrane member (45), disposed so as to surround and cover the heat exchange section that the absorbing liquid contacts, through which the refrigerant vapor can pass but the absorbing liquid cannot pass.