PURPOSE: To realize a high accuracy of boring machining by comparing the images before and after the boring machining so as to discriminate the machined hole, after boring machining is carried out at the mark center of a standard mark formed on a base.

CONSTITUTION: In this machined hole discriminating method of a camera type standard boring machine the machined hole 3 in a camera view field after a machined hole 3 is formed is extracted and the hole center is calculated, and then the mark center 2a of a standard mark 2 before the boring, and the hole center of the machined hole 3 are compared so as to discriminate the machined hole 3. consequently, a highly accurate discrimination of the process hole can be carried out constantly.