When examination at a scan speed equal to or higher than the line rate of the sensor such as a TDI sensor is carried out, the line rate of the TDI sensor is asynchronous with the scan speed, and the image is blurred. Therefore, a TDI sensor cannot be used at a scan speed equal to or higher than the line rate of the TDI sensor. This problem has not been considered. To solve the problem, high-speed examination irrespective of the line rate of the TDI sensor is enabled. To control the line rate of the TDI sensor and stage scan speed asynchronously and to solve the problem of the image addition variation due to the charge accumulation of the TDI sensor, the object to be examined is irradiated with thin-line illumination, and only a given pixel line of the TDI sensor is made to receive light scattered by the object to be examined. The aspect ratio of the detection pixel size can be controlled by the speed ratio between the line rate of the TDI sensor and the stage scan speed.