A substrate-treating apparatus includes a liquid-providing part, a first liquid-removing knife and a returning part. The liquid-providing part provides a first liquid chemical for cleaning a substrate that includes a metal pattern and a photoresist pattern on the metal pattern, and for removing an etchant that remains on the substrate. The first liquid-removing knife sprays a second liquid chemical in a direction inclined and opposite to a returning direction of the substrate, so as to remove the first liquid chemical, the first liquid chemical including a metal precipitate. The returning part returns the substrate from the liquid-providing part toward the first liquid-removing knife in the returning direction.