To detect detailed information of a fault required by little photosensors by precisely inspecting a fault detected by rough inspection of a line sensor by an area sensor having an area sensor driver movably supported along a web.

A feeding means feeds a strip-like web in its lengthwise direction. A line sensor 17 is arranged in a width direction of the web to roughly inspect presence or absence and position of a fault existing in the web. An area sensor 21 is provided at a downstream side in a feeding direction of the web from the sensor 17 to precisely inspect the defect roughly inspected by the sensor 17. The sensor 21 is movably supported on the web by an area sensor driver 31. And, a controller 41 drives the driver 31 to move the sensor 21 to a fault position of the web based on a detected result of the sensor 17 and feeding speed of the web.