Abstract: A method of operating an operator control and monitoring device for safety-critical applications in which the control and monitoring device includes a display and a touch-sensitive sensor, wherein a control element is shown on the display which an operator must touch to obtain an approval for a safety-critical application that is granted for as long as the control element is being touched, wherein first and second numbers of touch points are respectively displayed in first and second control zones, position data of the first and second control zones is selected such that the fingers of a human hand cannot simultaneously touch all touch points of the first and second control zones, and wherein the approval for the safety-critical application is only granted if all touch points from the first and second control zones are being touched.