A method of forming a pattern having a level difference on a substrate by means of a positive type photosensitive resin, comprising: a step of forming a layer of the photosensitive resin composition on the substrate, the photosensitive resin composition comprising at least an acrylic resin having a carboxylic anhydride structure in a molecule; and a compound that generates an acid when irradiated with light; a first photolithographic step for patterning said photosensitive resin layer in the thickness direction up to a predetermined depth to form a first pattern composed of a part protruding from the predetermined depth; and a second photolithographic step for further patterning said photosensitive resin layer in order to form a second pattern on which the first pattern is maintained, which forms an overall pattern having a level difference, characterized in that: the first lithography step includes process steps of exposure, heating after exposure, and development; a reaction for making the layer of the photosensitive resin composition positive in the first photolithographic step is derived from at least a hydrolytic reaction of a carboxylic anhydride in the acrylic resin; the second photolithographic step includes process steps of exposure and development; and a reaction for making the layer of the photosensitive resin composition positive in the second photolithographic step is derived from at least a main chain decomposition reaction of the acrylic resin. a step of forming a layer of the photosensitive resin composition on the substrate, the photosensitive resin composition comprising at least an acrylic resin having a carboxylic anhydride structure in a molecule; and a compound that generates an acid when irradiated with light; a first photolithographic step for patterning said photosensitive resin layer in the thickness direction up to a predetermined depth to form a first pattern composed of a part protruding from the predetermined depth; and a second photolithographic step for further patterning said photosensitive resin layer in order to form a second pattern on which the first pattern is maintained, which forms an overall pattern having a level difference, characterized in that: the first lithography step includes process steps of exposure, heating after exposure, and development; a reaction for making the layer of the photosensitive resin composition positive in the first photolithographic step is derived from at least a hydrolytic reaction of a carboxylic anhydride in the acrylic resin; the second photolithographic step includes process steps of exposure and development; and a reaction for making the layer of the photosensitive resin composition positive in the second photolithographic step is derived from at least a main chain decomposition reaction of the acrylic resin. the first lithography step includes process steps of exposure, heating after exposure, and development; a reaction for making the layer of the photosensitive resin composition positive in the first photolithographic step is derived from at least a hydrolytic reaction of a carboxylic anhydride in the acrylic resin; the second photolithographic step includes process steps of exposure and development; and a reaction for making the layer of the photosensitive resin composition positive in the second photolithographic step is derived from at least a main chain decomposition reaction of the acrylic resin.