A removable knob safety insert is installed in a cooking device such as a gas or electric stove, between and the rear face of its control knob and the face of its control panel. The knob safety insert is designed to manually control the activation or deactivation of the cooking elements, as desired. The push-in-and-turn type switches used in such devices require that the control knob be pushed in before the switch can be moved from its off position. When in its locked position, the knob safety insert prevents the control knob from being pushed and thus the cooking element from being activated. When in its unlocked position, the knob safety insert enables the control knob to be pushed, allowing the cooking element to be moved from its off position.