SOLUTION: Provided is a sterilized coating film formed by a production method comprising the steps of: (1) coating a substrate with a coating film-forming composition containing a radiation-degradable polymer and a solvent (2) drying the substrate to form a coating film and (3) subjecting the substrate to sterilization by radiation, and in which the steps (1) to (3) are sequentially carried out. Also provided is a method for producing the coating film.EFFECT: To provide a sterilized coating film by a very simple production method including: sterilization by radiation irradiation and sequential execution of coating, drying, sterilizing, and washing steps, without impairing a function (for example, a biological material adherence suppressibility) of the film even when a material which forms the film is a radiation-degradable polymer.SELECTED DRAWING: NoneCOPYRIGHT: (C)2016,JPO&INPIT