Disclosed is a method for making a disk-shaped filtering unit. In the method, there is provided a laminate by sandwiching a screen-related substrate between two permeable membrane-related substrates. There is provided a machine with a conveying unit, a hot-pressing unit and a punching unit. The conveying unit is used to convey the laminate. The hot-pressing unit is used to hot-press and weld the laminate dot by dot to bond the substrates along a closed curve eventually, thus making a semi-product of the filtering unit out of a portion of the laminate within the closed curve. There is made a final product of the filtering unit by using the punching unit to punch the semi-product with an aperture.