Abstract: An oil filter for providing coarse and fine filtration of lubricating oil in an internal combustion engine is disclosed herein. The oil filter includes a cylindrical housing closed by a cover containing a coarse-filtering cartridge of pleated paper included between a lower plate and an upper plate, and a fine-filtering cartridge placed between the coarse-filtering cartridge and the cover. The fine-filtering cartridge is supported between a lower base plate and an upper base plate arranged to bear against the cover. Both filtering cartridges have a cylindrical shape with axial recesses extending therethrough. The fine-filtering cartridge is composed of a band of filtering paper disks, the band being bent as an accordion. The upper base plate is integrally formed with to a first end of a barrel with the barrel coaxially extending through the axial recess of said fine-filtering cartridge and partially into the axial recess of said coarse-filtering cartridge.