To provide a safety device of a circular sawing machine which can prevent an operator from coming into contact with a saw blade by arranging so that the saw blade is always covered regardless of the thickness of a lamellar panel, in an operating process to cut the tabular panel using the circular sawing machine.

This safety device of the circular sawing machine is constituted of the following components: (1) a box cover 6 which is arranged in the way that it encircles the left/right, front/rear and top of the saw blade exposed on the table surface T of the circular sawing machine from above the saw blade 15, (2) a wheel 8 which is arranged on the tabular panel insertion side of the box cover through an axle 7 fitted to the box cover so as to allow the outer periphery of the wheel to come into contact with the table surface, and further, which is accompanied by the action to bring the lower end of the box cover into contact with the table surface or leave a gap of a few mm, in such a timely manner that the outer periphery of the wheel comes into contact with the table surface, (3) a slide mechanism which moves the box cover vertically to a base plate 2, with an arm 1 for setting the device, which is arranged at the upper end of the base plate and sets the device, and (4) protecting plates 11, 12 and 13 which are rotatably arranged directly or indirectly on the base plate in such a way that the above plates, covers both sides of the box cover and the lower end of the former reach the table surface T.