This invention provides a photoresist coating liquid supplying apparatus and a photoresist coating liquid supplying method, for supplying a photoresist coating liquid having a low particle content to a photoresist coating apparatus, and a photoresist coating apparatus using such a photoresist coating liquid supplying apparatus, which can realize coating without causing significant defects in a cost-effective manner.The photoresist coating liquid supplying apparatus comprises a buffer vessel for a photoresist coating liquid, a circulation filtering apparatus for drawing a part of the coating liquid from the buffer vessel, filtering the coating liquid, and then returning the filtered coating liquid to the buffer vessel, and a pipe for supplying the coating liquid from the buffer vessel or the circulation apparatus to a coating apparatus. The photoresist coating liquid supplying method uses the photoresist coating liquid supplying apparatus. The photoresist coating apparatus comprises a combination of the coating liquid supplying apparatus with a slit coating apparatus.