Device capable of automatically supplementing liquid ammonia for etching container

The utility model discloses a device capable of automatically supplementing liquid ammonia for an etching container. The device comprises a probe detecting the pH value of the etching liquid in the etching container, the probe is connected with a control unit, the control unit is connected with a liquid ammonia pump, and the liquid ammonia pump is arranged in a liquid ammonia storage tank. The control unit automatically controls the on/off of the liquid ammonia pump according to specific pH value of the etching liquid acquired by the probe. By adopting the device provided by the utility model, the automatic supplement is realized, the etching efficiency and effect can be effectively improved, and the pH value of alkali etching liquid can be kept within the range from 8.0 to 8.8, thereby generating no precipitation and preventing environmental pollution.