Provided is an image display apparatus which includes a display unit that displays a series of images obtained by imaging an inside of a subject in time sequence, and displays a specific area with a predetermined size; and an input unit having an input button group for performing a display operation of the images. For example, the functions may comprise a set of functions f1, f1,. To this end, the adjusting device comprises a first part with webs, which are interspaced in the peripheral direction and between which chambers are formed, and includes a second part with an internal gearing, and a number of teeth that are arranged inside the chambers while being interspaced in the peripheral direction. The container is then rotated at various speeds and the camera captures images of the powder at fixed time intervals.