Pattern forming method, a manufacturing method of an electronic device using the same, and an electronic device

Provided is a pattern forming method including, in the following order: (1) forming a resist film on a substrate; (2) exposing the resist film, and thereby forming a first line-and-space latent image; (3) subjecting the resist film in which the first line-and-space latent image has been formed, to a first heating treatment; (4) exposing the resist film that has been subjected to the first heating treatment, and thereby forming a second line-and-space latent image, so that the line direction in the second line-and-space latent image intersects the line direction in the first line-and-space latent image; (5) subjecting the resist film in which the second line-and-space latent image has been formed, to a second heating treatment; and (6) developing the resist film that has been subjected to the second heating treatment, using a developer containing an organic solvent.