When the operation function of an automatic analyzer is allowed to use, all selection buttons respectively provided in corresponding to a plurality of operation functions being grouped are displayed on a predetermined area of a CRT display. In this case, the button corresponding to the operation function allowed to be used for a particular operator is indicated by the color representing accessible, while the button corresponding to the operation function not allowed to be used for the particular operator is indicated by the color representing not-accessible. When the button corresponding to the accessible operation function is selected, the subclass operation function screens relating to the selected operation function are displayed in a hierarchy fashion or a multi-layer fashion.