A process for producing a high-cleanliness steel is provided which can produce, without relying upon a high-cost remelting process, steel products having cleanliness high enough to satisfy requirements for properties of mechanical parts used under severer environmental conditions. The production process comprises the steps of: transferring a molten steel produced in an arc melting furnace or a converter to a ladle furnace to refine the molten steel; subjecting the molten steel to circulation-type degassing; and casting the molten steel into an ingot, wherein, in transferring the molten steel to the ladle furnace, a deoxidizer includingmanganese, aluminum and silicon, is added to previously deoxidize the molten steel, that is, to perform tapping deoxidation before refining in the ladle refining furnace.