To quickly and accurately adjust a parallelism between the sliding direction of a body and a rotary cutting edge.

Connection between a front end 8 of a slide bar 6 and the body 10 is carried out by locating a base end 11 of the body 10 between a pair of brackets 9, 9 provided at the right and left of the front end 8 and rotatably fitting the base end 11 to both brackets 9, 9 by a support shaft 12. Each bracket 9 is rotatably provided with a sleeve 21 having an eccentric connecting hole 22 to which a small diameter part 20 of the support shaft 12 is insert-connected. With the rotating operation of the sleeve 21, the end of the support shaft 12 is tilted in a longitudinal direction to change the direction of a saw blade.