PURPOSE: To provide a system and a method for preparing hierarchically grouped macros.

CONSTITUTION: By selecting the recording start 230 of the macro from the menu item 226 of a graphic user interface 225 by an operator 201, a macro preparation mode is attained and respective key inputs and the operations of the operator are kept in a buffer 232. The operator 201 can make a selection from a system arithmetic operation 240 as well and can select a parameter from a system parameter file 242 for respective arithmetic operations as well. When the operator 201 selects the preparation end of the macro from the menu item 226 and a name is attached to the macro, the macro 250 is prepared from information stored in the buffer 232.