In a band saw machine in which a pair of guide posts for guiding a saw blade housing that rotatably supports a driving wheel and a driven wheel and can vertically move in the vertical direction are provided between the driving wheel and the driven wheel, an upper traveling part of a band saw blade is disposed in the rear of the guide posts and a lower traveling part of a band saw blade is disposed in front of the guide posts, when the band saw machine is viewed from the side, an intersection point between centers of the both wheels and the center line of the wheel width is almost equal to the width of the guide posts.