A digital camera is constituted of a camera body and a lens unit. The lens unit is removably attached to the camera body. When the lens unit is attached to the camera body, they are electrically connected through connection terminals. A nonvolatile memory in the lens unit previously stores a chart image that is obtained by capturing a resolving power chart representing image resolving power by a CCD. When an attachment detector of the camera body detects that the lens unit is attached to the camera body, the chart image is transferred into the camera body and is displayed on a LCD.