To move saw guides to a proper position between a cut starting position to a cut finishing position to minimize an unused part of a band saw corresponding to a work cutting length of the band saw.

A pair of saw guides 30, 31 are slidably supported on a saw frame 6 through a linear rail 26. The saw guides 30, 31 can be close to or separated from one another by a feed screw 27 which is a left and right inverse screw of equal pitches. Jaws 23a, 23b on a base 2 can be closed to or separated from one another by a feed screw 35 which is a left and right inverse screw of equal pitches. A work W is clamped by the pair of jaws 23a, 23b, an up-and- down cylinder 22 is driven to lower the saw frame 6, and the work W is cut. Opposite faces of the saw guides 30, 31 are recessed faces 24, and the saw guides 30, 31 are closest to one another during the whole cutting stroke from the cut starting position to the cut finishing position. The work W is stored between the recessed faces 24 of the saw guides 30, 31 when the cutting is finished.