A lawn mower in which an operating part that performs lawn mowing is equipped in a traveling machine body that travels in a field. The operating part comprises a rotary-driven bladed disk in a state of facing the field, and a cutting blade piece rockably mounted on an outer peripheral part of the bladed disk. A mounting part in which the cutting blade piece is mounted on the bladed disk comprises an axial member mounted to cross a field opposed surface of the bladed disk, and a cylindrical member which is hollow and into which the axial member is inserted with a space therebetween. The axial member is mounted on the bladed disk in a state in which the cutting blade piece is fixed to an outer periphery of the cylindrical member and the axial member is inserted into the cylindrical member.
