Apparatus for processing substrates according to a predetermined photolithography process includes a loading station in which the substrates are loaded, a coating station in which the substrates are coated with a photoresist material, an exposing station in which the photoresist coating is exposed to light through a mask having a predetermined pattern to produce a latent image of the mask on the photoresist coating, a developing station in which the latent image is developed, an unloading station in which the substrates are unloaded and a monitoring station for monitoring the substrates with respect to predetermined parameters of said photolithography process before reaching the unloading station.