Abstract: A miter box comprising a base having a flat top surface and opposed parallel elongated side edges. A pair of spaced apart side walls extend from at least one of the side edges transversely above the flat top surface. The side walls have a flat inner surface to form right angle walls with the flat top surface. A saw blade guide mechanism is provided between the pairs of side walls. The mechanism comprises an arcuate guide means adjacent each of the side edges intermediate the pair of side walls and disposed on a circular axis having a common center point. The guide means have a diametrical pivotal base member pivotally secured on the center point below the flat top surface. Support guide means is secured to the pivotal base member and extends transversely above the flat top surface and displaceable along an arcuate path between each pair of side walls.