A method for producing a composition, the method being for producing a composition using a stirring device provided with a stirring tank and a stirrer, includes a mixing step of charging a resin, an acid generator, and a solvent into the stirring tank, and a stirring step of stirring the mixture accommodated in the stirring tank, using the stirrer, in which a ratio c of a content of the acid generator to a total mass of the mixture is 0.3% to 2.5% by mass, the stirrer is provided with a rotatable stirring shaft, a plurality of support parts attached to the stirring shaft, and a plurality of stirring elements attached to each of end parts of the plurality of support parts, the shape and the arrangement of the stirring elements are specified, and the positions of the plurality of stirring elements are specified so as to satisfy a specific Expression (1).