PURPOSE: To provide a band saw machine which is never influenced by chips or cutting solution under a simple structure, and can automatically position a moving-side saw guide without particularly requiring the operation and time therefor, and automatically position the saw guide with speed and precision.

CONSTITUTION: A moving-side saw guide 42 is supported in such a manner as to be capable of sliding in the nipping direction of a material on a saw frame 2 by a vice mechanism 3, so that it is displaced in this direction by a position regulating hydraulic cylinder 43. The position regulating hydraulic cylinder 43 is connected to a nipping hydraulic cylinder 33 for imparting the nipping motion to the moving-side vice jaw 32 of the vice mechanism 3 by a conforming hydraulic circuit 5, and the moving-side saw guide 42 is moved by an equal distance in conformation to the movement of the moving-side vice joe 32.