MANUFACTURING METHOD FOR GAS DIFFUSION SHEET

In a manufacturing method for a gas diffusion sheet, when a first film is joined to a front end portion of a base material in a conveyance direction, a first joining material is made to penetrate a first overlapping portion where the first film and the base material are superimposed on each other, and the first film and the base material are thus joined to each other physically through the first joining material. When a second film is joined to a rear end portion of the base material in the conveyance direction, a second joining material is made to penetrate a second overlapping portion where the base material and the second film are superimposed on each other, and the base material and the second film are thus physically joined to each other through the second joining material.