PURPOSE: To enable the amount of exposure light to be accurately determined by a method wherein patterns of different dimensions close to a resolution limit are arranged adjacent to each other on a flat base, and the patterns are ascertained by an optical microscope or an electron microscope or electrically measured by probing.

CONSTITUTION: A common terminal 1 and conductor layers connected to the common terminal 1 through the intermediary of slit patterns 7 are provided, and the slit patterns 7 are formed of wirings which are separated by prescribed gaps respectively, where the slit patterns 7 are composed of a first slit pattern provided with a minimum slit which can be resolved only when an exposure light volume is optimal and other slit patterns provided with slits which increase or decrease successively by stages in dimension by 0.1μm. In a metal wiring composed of six pads of aluminum alloy and wiring patterns connected to the pads, a pad 1 is a common pad, and it is measured that the pad 1 is electrically connected to or insulated from pads 2-6 respectively. By this setup, it is can be judged that the amount of exposure light is optimal or not.