Manufacturing method of semiconductor device

After forming a resist film on a Si substrate, a circuit pattern for a semiconductor integrated circuit, a first L-shaped length measuring pattern and a cross-shaped monitor pattern for alignment are formed on the resist film. Next, based on these patterns, the Si substrate is patterned. Thereafter, a polysilicon film is formed above the Si substrate. Subsequently, a resist film is formed on the polysilicon film. Next, a circuit pattern for a semiconductor integrated circuit, a second L-shaped length measuring pattern and a cross-shaped monitor pattern for alignment are formed on the resist film. At this time, the second L-shaped length measuring pattern is made to face in a direction in which the first L-shaped length measuring pattern is rotated 180 degrees in plane view. By patterning the polysilicon film with these patterns as a mask, a gate electrode is formed.