A stereo camera and an examination screen having a pattern based on grid lines are arranged at prescribed positions relative to each other. The stereo camera photographs the examination screen to obtain two original images. A stereoscopic image characteristics detection unit obtains the coordinates of each grid point on each image. A correction data generation unit generates correction data for correcting a variation in the image characteristics on the basis of the obtained coordinates and the corresponding ideal coordinates stored previously of each grid point. A correction data writing unit writes the generated correction data into a stereoscopic image recognition unit. Thus, prior to shipment of the stereo camera and the stereoscopic image recognition unit or upon readjustment after shipment, the characteristics of an stereoscopic image are examined to obtain high-accurate correction data. The high-level capability of the stereo camera is maintained using the correction data.