To extend the using condition in an appearance inspection device for inspecting the appearance of a cylinder or cylindrical article by use of image processing technique to facilitate the setting and also reduce the cost.

A cylindrical mirror 11 and a camera 9 are substantially concentrically arranged to a work W, and the inspection part of the work W projected to the inside surface 11a of the cylindrical mirror 11 is imaged by the camera 9. The inspection image for projecting the whole circumference of the inspection part of the work W can be obtained by use of one camera to reduce the cost and save the space for the whole device. A continuous homogeneous image without interruption can be provided as the inspection image to improve the precision of inspection.