A pattern forming method includes (A) a step of forming a first resist film on a substrate by using a first resist composition, (B) a step of exposing the first resist film, (C) a step of forming a first pattern by developing the exposed first resist film, (D) a step of forming a planarization layer on the substrate provided with the first pattern by using composition for forming a planarization layer (a), (E) a step of forming a second resist film on the planarization layer by using a second resist composition, (F) a step of exposing the second resist film, and (G) a step of forming a second pattern by developing the exposed second resist film in this order, in which the first pattern is insoluble in the composition for forming the planarization layer (a), and a method for manufacturing an electronic device using the pattern forming method.