To provide confirming tool and method by which in constructing PC-made foundation using a PC-made foundation block, the position of an anchor bolt and face line of the side surface of the outside of the PC-made foundation can be confirmed, or if slipped, adjustment can be made surely.

By this anchor bolt position and face line confirming tool 10, a precast concrete-made foundation block is used for a rising part, and concrete is placed below that to construct an inverted-T shaped building foundation. In that case, the confirming tool 10 is so constructed that a vertical plate 12 is suspended from one end edge of an oblong flat upper plate 11 to form an L-shaped main body 1, the main body is provided with an anchor bolt insert hole 2 and a pin 4 as a reference point for tensing a leveling string which are on the same line intersecting perpendicularly to the vertical plate 12 of the upper plate 11, and also a pin 3 as a reference point for tensing a leveling string is erected on the corner part on the line which agrees with the side surface of the outside of the PC-made foundation of the upper surface of the upper plate 11.