PURPOSE: To remove the unnecessary resist stuck on the rear surface of a photomask, etc. simultaneously with surface development by rotating a horizontally held substrate around a vertical shaft, and providing nozzles for spraying developing solns. to the front and rear surfaces from both top and bottom of the substrate.

CONSTITUTION: In a photomask, etc. used for producing stages for integrated circuits wherein a metal layer 2 and a resist layer 3 are provided successively on the surface of a transparent substrate 1, a substrate 4 after pattern exposure is held horizontally by a vacuum chuck 5 in order to remove the unnecessary resist 7 stuck on the rear surface of the substrate 1 by turning round thereto. While the substrate is rotated around the vertical shaft of the chuck 5, a nozzle 6 for developing soln. is provided above the substrate 4 and a nozzle 8 for developing soln. below the substrate 4, and developing solns. are sprayed simultaneously to the front and rear surfaces of the substrate 4. Thus the unnecessary resist 7 is removed simultaneously with developing of the surface resist layer. The generation of defects by dust, etc. is prevented by the operation for stipping the resist 7 after the surface development.