Abstract: In fabrication of a semiconductor device having plural patterns on a plurality of layers by using complementary divided masks each having alignment marks distributed therein, because of the presence of a plurality of complementary divided mask layers, misalignment between respective layers tends to occur. To solve this problem, divided alignment marks (M1a, M2a, M3a, M4a) are formed in respective complementary divided regions corresponding to respective blocks (B1, B2, B3, B4) of complementary divided masks obtained by dividing a stencil mask. By distributing alignment marks to respective complementary divided masks, a positional deviation between respective masks is averaged, thereby enabling to fabricate a semiconductor device in which a large positional deviation between patterns of adjoining layers is eliminated.