A cutter machine may include a first blade, a second blade configured to rotate relative to the first blade, a base member supporting the first blade and the second blade, a screw member including a head portion and a shaft portion extending from the head portion which is a proximal end of the shaft portion, wherein the screw member fastens the first blade and the base member to each other, a looseness restraint member attached to the shaft portion and configured to be pressed by the head portion to restrain loosening of the screw member, and a fall-off restraint member attached to the shaft portion on a distal side of the shaft portion relative to the looseness restraint member and configured to restrain the looseness restraint member from moving relative to the shaft portion in a direction from a proximal side to the distal side of the shaft portion.