The CHaracterizing ExOPlanet Satellite (CHEOPS) is the first ESA S-type mission, and will be the first to search for transits by means of ultrahigh precision photometry on bright stars already known to host planets, and was launched in December 2019. Among the planets observed by CHEOPS, super-Earths will take a privileged position. They are the larger and more massive siblings of our Earth but will permit many studies of processes that are extremely relevant and important to the structure and evolution of our atmosphere. CHEOPS will identify planets with significant atmospheres in a range of masses, distances from the host star, and stellar parameters. Using observations of a sample of planets with and without significant gaseous envelopes, CHEOPS will be able to constrain the critical core mass (in the case of runaway gas accretion) or the loss of primordial H/He atmospheres as a function of the distance to the star and possibly stellar parameters (mass, metallicity).