To accurately and automatically measure at least the degrees of misalignment of end faces of a layered bundle and inclination of the layered bundle, as a load condition of the bundle of layered square planographic printing plates.

A measuring sensor 22 is scanned in the vertical direction by a movement means 24, and horizontal distance data from the measuring sensor 22 to four end faces 12A of the layered bundle 12 is obtained. Based on the horizontal distance data, a computer 26 calculates the conditions of misalignment of the end faces 12A and inclination of the layered bundle 12.