To make a machine comfortably usable by very tall or short user by installing a variable device which has a driving source and varies the height or the inclination of the display a device and a control means which drive- controls the variable device based on the user information.

A stand 32 is provided with the inner cylindrical object 33 of a rectangular shape, which is erected in a state where a lower end is fixed to a base part 31, and an outer cylindrical object 34 which is formed in the rectangular shape circumscribing the inner cylindrical object 33, guided by the inner cylindrical object 33 and freely and vertically slides. It can be extended/contracted in a vertical direction. An ascending/descending-variable device 35 extending/contracting a stand 32 is installed in the stand 32. A controller recognizes the image of a user from an image that a CCD camera 64 takes in and judges whether the head of the image of the user is in a prescribed height range or not on an image memory. A casing is extended/contracted while informing the user of it, that height is to be changed, through display or by sound.