To provide a cutter knife for slash quilts utilizing guide members of various full width dimensions without requiring exchange operation of the guide members.

The cutter knife for the slash quilts is equipped with the plurality of guide members 21-24 having different width dimensions and installed extendedly parallel to each outer tangent line to a circular blade 15 on the outer peripheral part of the cutter knife body 10 holding the circular blade 15. Slits 21a-24a are provided between each of the guide members 21-24 and the cutter knife body 10 to expose edges 15a of the circular blade 15 in the slits. Since one cutter knife 1 has the plurality of guide members having the different width dimensions, one of the plurality of guide members can suitably be selected and used for general purposes when various slash quilt fabrics having different pitch dimensions between stitches are manufactured. In the process, the exchange operation of the guide members is not required at all.