Method for determining the duration of a cleaning cycle of a thermal process for cleaning a cooking chamber in a cooking appliance , in which sensor signals from an optical sensor are fed to an electronic evaluation system which uses the sensor signals to determine the degree of soiling of the cooking chamber by evaluating the sensor signals , characterised in that a camera is used as the optical sensor , which generates a plurality of camera images as sensor signals during the course of a cleaning cycle, the camera images are transmitted from the camera to the electronic evaluation system , and the electronic evaluation system evaluates the transmitted camera images by means of image processing software by determining a degree of soiling of the cooking chamber for each camera image and deriving a current value for the remaining duration of the cleaning cycle from the most recently determined value for a degree of soiling , at least a first camera image being created close to the start of the cleaning cycle in order to obtain a first prediction for the duration of the cleaning cycle that has started, and at least a second camera image being created at a later point in time, the degree of soiling of the cooking chamber being determined by comparing the current camera image with stored camera images, the degree of soiling of the cooking chamber being used by the electronic evaluation system to evaluate whether and for how long the cleaning cycle is to be continued, and a switch-off signal for switching off a cleaning cycle and/or a signal for reducing the temperature in the cooking chamber being generated in the appliance electronics system if the electronic evaluation system has detected a sufficiently clean cooking chamber as part of the image evaluation. a camera is used as the optical sensor , which generates a plurality of camera images as sensor signals during the course of a cleaning cycle, the camera images are transmitted from the camera to the electronic evaluation system , and the electronic evaluation system evaluates the transmitted camera images by means of image processing software by determining a degree of soiling of the cooking chamber for each camera image and deriving a current value for the remaining duration of the cleaning cycle from the most recently determined value for a degree of soiling , at least a first camera image being created close to the start of the cleaning cycle in order to obtain a first prediction for the duration of the cleaning cycle that has started, and at least a second camera image being created at a later point in time, the degree of soiling of the cooking chamber being determined by comparing the current camera image with stored camera images, the degree of soiling of the cooking chamber being used by the electronic evaluation system to evaluate whether and for how long the cleaning cycle is to be continued, and a switch-off signal for switching off a cleaning cycle and/or a signal for reducing the temperature in the cooking chamber being generated in the appliance electronics system if the electronic evaluation system has detected a sufficiently clean cooking chamber as part of the image evaluation. <EOS>