To cut a work W to be smooth in a state near dry cutting by spraying lubricating oil mist to the cutter part of a saw blade and eliminating chips produced following the cutting of the saw blade by air suction.

While lubricating oil mist is sprayed from the spray ports 61a and 61b of mist jetting devices 6A and 6B to the cutter part 20 of a rotary- driven saw blade 2A, the saw blade 2A is contacted with a work W for cutting by the tilting of a tilt frame 3. Chips produced during this cutting are sucked into a suction duct 7 together with air and eliminated. At this time, lubrication oil mist has very small mist particles, and thus the mist is uniformly supplied to the front face of the cutter part 20 by spraying of a small amount, a good lubricating operation is performed, and the friction of a cut part P1 is greatly reduced. Thus, the work W is cut to be smooth in a state near dry cutting.