The actinic ray-sensitive or radiation-sensitive resin composition, a pattern forming method, and a method for manufacturing an electronic device

Focus tolerance is large and, actinic ray-sensitive or radiation-sensitive resin composition excellent in resolution, a pattern forming method using the composition, and provides a method for manufacturing an electronic device. The composition contains a resin (P), wherein the resin (P) is a repeating unit (a) having an acid-decomposable group, a repeating unit having a lactone structure, etc. (b), the repeating unit (a) comprises at least a repeating unit (a1) represented by a specific general formula (1), the content of the repeating unit (a1) with respect to the total repeating units in the resin (P) is 35 mol% or more , and the above resin (P) is a group represented by a specific general formula (X1), a structure represented by a specific general formula (X2), hydroxy adamantyl group, and a hydroxy group of the hydroxy adamantyl group is an acid It does not contain any decomposed protected group desorption radicals by the action of an actinic ray-sensitive or radiation-sensitive resin composition.