The present invention provides a semiconductor device manufacturing line for applying a series of processes on a semiconductor substrate, and forming an integrated circuit on the semiconductor substrate by employing a semiconductor wafer having a diameter of 6 inches (150±3 mm: SEAJ specification) or less for the semiconductor substrate. This manufacturing line comprises two sub-lines conforming to the same specifications, each of these sub-lines is composed of a series of processing units including a film forming unit, a pattern exposure unit, an etching unit, and a test unit. In at least one pattern exposure unit and one etching unit, fine processing of 0.3 μm or less can be performed.