We developed the improved absorption heat pump to promote industrial application and obtained the following results. 1. Simplification of a unit and the improvement of heat transfer performance were realized by the tube-side falling film design. 2. Limit of output temperature could be raised up to 200-degrees-C with BTA as the most suitable corrosion inhibitor. 3 Weight reduction of a unit by about 40% compared to our conventional design and cost reduction could be realized. 4. The first commercial unit based on the improved technology of 5 Gcal/h is under manufacture.