To prevent acetic acid, sulfurous acid and the like from being distilled into a distillate by providing a heating evaporation part and a gas-liquid contacting means for each of two or more liquids and providing, in a route from the heating evaporation part to a cooling condensation part for a liquid, a gas-liquid contacting means for a liquid other than it in a communicative state.

In an evaporating concentrator for evaporating and concentrating waste liquid such as photographic processing waste to dump it, after a heat transfer medium is compressed by a compressor 80 and is air-cooled and condensed by an air-cooled condenser 86, it is circulated in heat radiation parts 44, 34 of kettle parts 40, 30 for heating and evaporating waste liquid, a capillary tube 95, a heat absorption part 64 and a cooling coil 52. A waste liquid is fed into the kettle part 30 from a gas-liquid contacting means 40, and another waste liquid is fed into the kettle part 40 from a gas-liquid contacting means 25, and they are each concentrated and evaporated in the kettle parts 40, 30. The generated vapor is cooled and condensed in a kettle 50 after gas components thereof are absorbed in the gas-liquid contacting means 25, 26. After the distilled water is sent to a water flow tank part 60 and is temporarily stored, it is discharged to sewage or the like.