To efficiently recover cutting chips of a dry cutter and facilitate disposal of recovered cut chips.

An air blower 3 is started, an air flow is injected into a cutting groove from a blowoff port 40 and a blade 1 is cooled while generated cut chips are blown off and suspended in air. Since a valve 42 is throttled and the volume of air injected is reduced and made smaller than the volume of air sucked and the outside air is sucked to the inside from an opening between the skirt of a blade cover 10 and a road surface, cut chips do not leak from the opening. Since cut chips reach a cyclone 2 from a suction duct 11, are separated and deposits on a bottom section, a bottom plate 21 is opened and recovered into a dust collecting bag 23. Since the suction air flow is returned to a suction port for the air blower 3 through a filter 4 and circulated, an exhaust is not discharged to the outside air, and an environmental pollution can be reduced largely, and the frequency of the exchange of the filters is decreased because cut chips are separated by the cyclone 2.