The present invention provides a liquid supplying unit, including: a nozzle; a liquid supply pipe configured to supply a treatment liquid to the nozzle; and an impurity removing unit installed in the liquid supply pipe to remove an impurity in the treatment liquid, in which the impurity removing unit includes: a measuring unit configured to measure a characteristic of the impurity in the treatment liquid and form impurity data; a vibrating unit configured to apply vibration to the treatment liquid; a capturing unit configured to adsorb the impurity in the treatment liquid to which the vibration is applied; and a control unit configured to control the measuring unit and the vibration unit, and when the impurity data exceeds a reference data range, the control unit operates the vibrating unit.