To provide a photographic processing liquid manufacturing apparatus which prevents photographic processing liquid fed from a solution tank 101 to a storage tank 104 from being oxidized more than before, to provide a photographic processing liquid manufacturing apparatus which manufactures excellent photographic processing liquid without bubbling nor splashing the liquid when the liquid is fed, and to provide a photographic processing liquid manufacturing apparatus whose frequency of maintenance can be decreased and which is durable.

When the maximum value Sao of the area by which a flexible oxidation preventive sheet 109 can cover a liquid surface is larger than minimum value Sfl of the area of the liquid surface, the entire liquid surface can be covered with the area from at least Sfl to Sao even if the area of the photosensitive processing liquid surface in the storage tank 104 varies as the liquid is fed by a liquid feeding means 103, so oxidation prevention effect is greatly improved.