PURPOSE: To eliminate harmful material in contained liquid automatically by operating an air blowing means till the temperature of the liquid reaches a predetermined value in the heating mode for aerating the liquid during the while, and dispersing the material in the liquid with the blown air to the external.

CONSTITUTION: When an electromagnetic pump 14 operated, air is blown from a discharge port 17a into contained liquid 18. A bubble breaking mesh 19 is provided at the discharge port 17a, so air sent from air supply pipes 16, 17 becomes fine bubbles to be blown into the liquid 18 for turbulence contact with the liquid 18. At this time, uprising air stays in a space formed between an inner cover 9 at an upper part of an inner container 2 and the liquid 18 to pressurize the liquid surface. The contained liquid is injected by this pressure through a guide passage 20 of which base end is connected with the bottom part of the inner container 2. Simultaneously with it, the liquid is well aerated by turbulence contact with the fine bubbles, so such a chlorine, etc., dispersing action like that for water left in open air for a long period can be applied. Even for a water injecting action for a short time only, lime eliminating effect is achieved because the action is repeated.