An imaging device includes a camera, a robot that moves the camera, and a controller that processes an image. A detection surface defined on a workpiece and a set position serving as an imaginary position of the robot for detecting the workpiece are determined in advance. The camera captures a plurality of first images at a plurality of positions. The controller includes an image conversion unit converting the plurality of the first images into a plurality of second images when captured at the set position. The controller includes a composition unit generating a composite image into which the plurality of the second images are composited, and a composite image processing unit performing at least one of detection and inspection of the workpiece on the detection surface on the basis of the composite image.