An operating unit for an injection molding machine, comprising - a touch-sensitive display screen for displaying an operating program, - a control or regulating unit for communicating operating signals to injection molding machine elements, wherein the operating program is stored in the control or regulating unit, and - at least one operating button, upon the actuation of which the control or regulating unit triggers an action of an injection molding machine element, wherein the operating program has a hierarchical system architecture with - at least one upper installation-specific level, wherein a selection can be made between different installation regions (L1-L5) in the installation-specific central level, and - an upper task-specific level, wherein a selection can be made between different task regions (F1-F5) in the task-specific central level, and - a plurality of sublevels (U1-U6), wherein process-relevant program pages associated only with the selected installation region (L1-L5) or only with the selected task region (F1-F5) can be displayed in each selected sublevel (U1-U6), wherein - either when starting the operating program one of the two upper levels (M1, M2) is automatically pre-selected, wherein a button for the respective non-selected upper level (M1, M2) is displayed and wherein the different installation regions (L1-L5) or the different task regions (F1-F5) respectively are suitably displayed by actuation of that button, or wherein - the hierarchical system architecture comprises a main level in which a selection can be made between an installation-specific menu and a task-specific menu, wherein two start points are displayed in the main level, those start points representing the installation-specific menu and the task-specific menu, wherein - if the installation-specific menu or the task-specific menu is selected - then the operating program changes and the display on the display screen correspondingly changes into the upper installation-specific level or into the upper task-specific level respectively. - a touch-sensitive display screen for displaying an operating program, - a control or regulating unit for communicating operating signals to injection molding machine elements, wherein the operating program is stored in the control or regulating unit, and - at least one operating button, upon the actuation of which the control or regulating unit triggers an action of an injection molding machine element, - at least one upper installation-specific level, wherein a selection can be made between different installation regions (L1-L5) in the installation-specific central level, and - an upper task-specific level, wherein a selection can be made between different task regions (F1-F5) in the task-specific central level, and - a plurality of sublevels (U1-U6), wherein process-relevant program pages associated only with the selected installation region (L1-L5) or only with the selected task region (F1-F5) can be displayed in each selected sublevel (U1-U6), - either when starting the operating program one of the two upper levels (M1, M2) is automatically pre-selected, wherein a button for the respective non-selected upper level (M1, M2) is displayed and wherein the different installation regions (L1-L5) or the different task regions (F1-F5) respectively are suitably displayed by actuation of that button, - the hierarchical system architecture comprises a main level in which a selection can be made between an installation-specific menu and a task-specific menu, wherein two start points are displayed in the main level, those start points representing the installation-specific menu and the task-specific menu, wherein - if the installation-specific menu or the task-specific menu is selected - then the operating program changes and the display on the display screen correspondingly changes into the upper installation-specific level or into the upper task-specific level respectively.