| abstract |
In the present invention, a method for producing a porous polymer film comprises a step (I) for irradiating a polymer film with an ion beam constituted of accelerated ions to form a polymer film that has been bombarded with the ions in the beam; and a step (II) for chemically etching the polymer film formed in step (I) to form, in the polymer film, openings and/or through holes corresponding to the trajectories of bombardment of the ions. Step (I) involves the following: arranging the polymer film in an atmosphere having a pressure of 100 Pa or greater; passing the ion beam through a beam line held at a pressure lower than that of the atmosphere as well as a pressure partition sheet separating the beam line and the atmosphere, the pressure barrier sheet being arranged at a terminus of the beam line; and irradiating the polymer film which is in the atmosphere. |