To provide a handsaw jig which cuts a wood board exactly in a prescribed length by needing no ruled line writing.

A measuring/cutting tool is used to cut a flat lumber block in a prescribed length. A dimensional scale is described on the upper surface of a flat lengthy body 2. At one end of the body, the handsaw jig 3 is arranged/fixed so that a cutting position is a zero position on the dimensional scale when a saw plate S is sawed along a saw blade guide plate 32. The body 2 is moved along the end surface of the lumber block to be cut when used.