To provide a scanning exposing method making no uneven joints and no defective shapes when using an exposing device having two or more exposing heads.

This is a method of sequentially exposing the stripe patterns of the masks mounted on the exposing heads A, B, one by one overlapping their edges to continue on the exposing area of a large substrate running under the exposing heads by using a scanning exposing device. The masks have the main stripe patterns 2a, 3a with regular spacing and the edge stripe patterns 2b, 3b with spacing larger than the main stripe patterns respectively. The edge stripe patterns of the mask overlapping at the edges are put together on the exposed area by exposing with the exposing head to form the stripe patterns with regular spacing.