A working part (13) of a lawnmower (10) includes a disk (20) rotatably supported by a main body of the lawnmower and configured to be rotated by a power source (15), a blade (36) having a base end portion (46) rotatably attached to an outer peripheral part of the disk via a pivot shaft (32) and a free end portion (47) configured to protrude radially outward from an outer peripheral edge of the disk, and a blade guard (37) having a base end portion (51) rotatably supported by the pivot shaft and a free end portion (52) overlying the free end portion of the blade.