Method and device for controlling hatching hatching, wherein physical or chemical quantities characteristic of this hatching are measured or controlled in a hatching chamber during the hatching process, and furthermore the non-invasive of at least the hatching of the egg a chick of at least a first egg of a particular set of hatching eggs is measured, and based on this measurement, measurement control signals are obtained, subsequently and within a specified time interval calculated from said measuring, at least the concentration of CO2 in said hatching chamber is changed.
