PURPOSE: To provide an evaporation-concentration apparatus which regenerates waste liquid of photographic photosensitive material treatment into a concentrate and distilled liquid without generating odors, utilizes the distilled liquid as a water resource repeatedly for development treatment, recovers the concentrated liquid efficiently to make the disposal procedure easy, is of low energy consumption, and can be adequately used even in a small-scale laboratory and a treatment method using the apparatus.

CONSTITUTION: In this heat pump type evaporation-concentration apparatus in which a compressor 21, heat radiation parts 2A, 2B, an expansion valve 26, and heat absorption parts 8A-8C are connected in sequence, the heat radiation parts of a heat pump circuit in which a heat medium is sealed are used as the heating means of heat evaporation parts A, B for liquid which is subjected to evaporation-concentration, the heat absorption parts 8A-8C are used as the cooling means of cooling-condensation parts A, B for cooling and condensing vapor generated from liquid.