PURPOSE: To simplify the device concerned and make it possible to realize highly efficient dust collection by a method wherein the end opening of a saw cover surrounding a circular saw is faced to a through-like housing box, which is arranged in the travelling direction of the circular saw and dust-collecting means, which removes sawdusts by suction, is connected to proper places of the housing box.

CONSTITUTION: A dust collecting cover 18, which is mounted to a saw bed 5 surrounding a circular saw 11, is a tubular one with both ends open. Further, the upper end opening (a) of the cover is arranged near the under surface of a table 2, while its low end opening (b) is arranged so as to extend downwards. A housing box 19 of saw dust, which is arranged in the travelling direction of the saw bed, is made in the shape of a trough blocked up with cover pieces, each of which is flexible upwards. The lower end opening (b) faces through the clearance made between the cover pieces 20 to the housing box 19. A sweeping-away member 21, which is mounted downwards at the lower end part of the dust collecting cover 18, is produced by planting brush 22 to a mounting plate 23 so as to conform to the cross-sectional form of the housing box 19. Dust-collecting ports 24 and 25, which are provided at both the ends of the housing box 19, are connected to vacuum means, which removes dust by suction.