To provide a grinder for wood with branches and leaves enhanced in durability without causing any deformation and equipped with a chip discharge duct capable of certainly and safely performing undulation operation.

This automatic travelling grinder for wood with branches and leaves is constituted by providing a housing (6) housing a crushing part for cutting and grinding wood with branches and leaves and a ground piece discharge part, an on-off cover body (6b) of the housing, a ground piece discharging opening (6c) of the on-off cover body (6b), a chiip discharge duct (22) communicating with the opening (6c) and a deflector (24) supported and fixed to the chip discharge duct (22) so as to be turnable around the axis in the direction crossing the axial line of the chip discharge duct (22). In a state that the rear end of the deflector (24) turning around the axis protruded from the surface of the chip discharge duct (22) is earthed by the opening of the on-off cover body (6b), a length from the axis to the rear end of the deflector is set to a length (L1) capable of preventing the earthing of the lowermost end of the chip discharge duct (22).