An alignment mark formed by using a first mask used in forming a same memory cell pattern on a substrate and formed together with the memory cell pattern includes: a first pattern for position detection used for alignment in forming a first wiring pattern; and a first irregular reflection prevention mark that suppresses, when a position detection signal is irradiated as alignment in forming a second wiring pattern further on an upper layer side than the first wiring pattern, irregular reflection of a position detection signal from a second pattern for position detection formed further in a lower layer than the first pattern for position detection.