An active light sensitive or radiation sensitive resin composition which contains (A) an acid-decomposable resin, (B) a compound represented by general formula (bl), and (C) a compound represented by general formula (c1), wherein the ratio of the content of the compound (C) to the content of the compound (B) is from 0.01% by mass to 10% by mass; an active light sensitive or radiation sensitive film which uses this active light sensitive or radiation sensitive resin composition; a pattern forming method; and a method for producing an electronic device. In the formulae, L1 represents a single bond or a divalent linking group; A represents a group that is decomposed by the action of an acid; each B represents a group that is decomposed by the action of an acid, a hydroxy group or a carboxy group, provided that at least one B represents a hydroxy group or a carboxy group; n represents an integer from 1 or 5; X represents an (n+1)-valent linking group; and M + represents a sulfonium ion or an iodonium ion.