A manufacturing method of a solar cell which includes a cured polyimide film formed with cured polyimide as part of a structure of the solar cell, the manufacturing method comprising: a step of forming a pn junction which joins a p-type layer and an n-type layer within a semiconductor substrate; a step of forming a p-type electrode which electrically contacts the p-type layer; a step of forming an n-type electrode which electrically contacts the n-type layer, a step of forming a p-type bus bar connected to the p-type electrode; and a step of forming an n-type bus bar connected to the n-type electrode; wherein the cured polyimide film is applied in a pattern in positions to insulate the n-type bus bar from the p-type electrode and the part to insulate the p-type bus bar from the n-type electrode; the manufacturing method further comprising the steps when forming the cured polyimide: a step of applying a polyimide paste which includes an organic solvent and a polyimide resin dissolved in the organic solvent, and which becomes the cured polyimide by being cured as a result of being dried and heated, to a surface of a structure including the semiconductor substrate; a step of, after applying a polyimide paste, applying a solvent including a polar material of at least one type among water, ethylene glycol, acetic acid, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and formic acid, to a surface of the structure including the semiconductor substrate at least at a portion where the polyimide paste is applied; a step of, after applying the solvent including the polar material, drying the polyimide paste and the solvent including the polar material; and a step of heating and curing the dried polyimide paste to form the cured polyimide film. a step of forming a pn junction which joins a p-type layer and an n-type layer within a semiconductor substrate; a step of forming a p-type electrode which electrically contacts the p-type layer; a step of forming an n-type electrode which electrically contacts the n-type layer, a step of forming a p-type bus bar connected to the p-type electrode; and a step of forming an n-type bus bar connected to the n-type electrode; wherein the cured polyimide film is applied in a pattern in positions to insulate the n-type bus bar from the p-type electrode and the part to insulate the p-type bus bar from the n-type electrode; the manufacturing method further comprising the steps when forming the cured polyimide: a step of applying a polyimide paste which includes an organic solvent and a polyimide resin dissolved in the organic solvent, and which becomes the cured polyimide by being cured as a result of being dried and heated, to a surface of a structure including the semiconductor substrate; a step of, after applying a polyimide paste, applying a solvent including a polar material of at least one type among water, ethylene glycol, acetic acid, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and formic acid, to a surface of the structure including the semiconductor substrate at least at a portion where the polyimide paste is applied; a step of, after applying the solvent including the polar material, drying the polyimide paste and the solvent including the polar material; and a step of heating and curing the dried polyimide paste to form the cured polyimide film. a step of applying a polyimide paste which includes an organic solvent and a polyimide resin dissolved in the organic solvent, and which becomes the cured polyimide by being cured as a result of being dried and heated, to a surface of a structure including the semiconductor substrate; a step of, after applying a polyimide paste, applying a solvent including a polar material of at least one type among water, ethylene glycol, acetic acid, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and formic acid, to a surface of the structure including the semiconductor substrate at least at a portion where the polyimide paste is applied; a step of, after applying the solvent including the polar material, drying the polyimide paste and the solvent including the polar material; and a step of heating and curing the dried polyimide paste to form the cured polyimide film.