PROBLEM TO BE SOLVED: To provide a method for producing a disposable diaper having an excellent touch of a heat-sealed fiber sheet even if the disposable diaper is formed by heat-sealing fiber sheets to one another.SOLUTION: The method for producing the disposable diaper includes a step of directly or indirectly heat-sealing a first fiber sheet and a second fiber sheet by holding the sheets between a first block and a second block. The first block has a first contact surface in contact with the first fiber sheet, and a second block has a second contact surface in contact with the second fiber sheet. At least one of the first contact surface and second contact surface has a high heat conductive part made of metal and a low heat conductive part made of ceramics with a lower thermal conductivity than metal.
