Abstract: A sharpening guide for a chain saw with a vertical longitudinal channel which is placed on a saw chain and saw bar in a straddling position enabling the guide to move along the chain and bar while filing right hand and left hand cutters. The guide includes two transverse channels; six fixed transverse filing angles consisting of 30, 35 and 40 degrees with file and guide alignment lines; four 10 degree pitch filing angles; a detachable spacer to eliminate saw chain side movement or wobble; and an alignment and locking mechanism consisting of three adjustable bolts which holds the guide squarely and firmly in place allowing the operator to use both hands when filing cutters.