To stably fit a saw to an article to be machined by supporting a shoe to be freely rotated around a pivot shaft and placing the pivot shaft nearly close to a cutting edge so as to move the pivot shaft almost at the same time when the cutting edge is moved through the article to be machined.

A pivot shaft 39 formed by pivot connecting between a shoe 24 and a shoe support 26 is placed nearly close to the cutting edge of a saw blade 18 and moved almost at the same time when the cutting edge is moved through an article to be machined. Herein, since the cutting edge is inclined with respect to the reciprocating movement of the saw blade 18, by the adjustment of the shoe support 26 for slightly changing the position of the cutting edge with respect to the pivot shaft 39 during reciprocating of the saw blade 18, a positional relationship between the pivot shaft 39 and the cutting edge is also changed.