A pattern forming method includes, in this order, forming a film on a substrate, using an active-light-sensitive or radiation-sensitive resin composition containing a resin (A) which has a repeating unit having a phenolic hydroxyl group, and a repeating unit having a group that decomposes by the action of an acid to generate a carboxyl group, and a compound (B) that generates an acid upon irradiation with active light or radiation; exposing the film; and developing the exposed film using a developer including an organic solvent, in which the developer including an organic solvent contains an organic solvent having 8 or more carbon atoms and 2 or less heteroatoms in the amount of 50% by mass or more.