To inspect a board, first, a measurement area is set on the board and a reference data of the measurement area is obtained. Then, a measurement data of the measurement area is obtained per colors, and a lighting condition is set using the reference data of the measurement area and the measurement data obtained per colors. Next, a feature object in the measurement area is set, and a distortion quantity between the reference data and the measurement data is obtained by comparing the reference data corresponding to the feature object and the measurement data corresponding to the feature object obtained under the lighting condition. Then, an inspection area is set by compensating the distortion quantity. Therefore, it is possible to compensate the distortion and set precisely the inspection area.