A micromechanical sensor that is produced surface-micromechanically includes at least one mass element formed in a third functional layer that is non-perforated at least in certain portions. The sensor has a gap underneath the mass element that is formed by removal of a second functional layer and at least one oxide layer. The removal of the at least one oxide layer takes place by introducing a gaseous etching medium into a defined number of etching channels arranged substantially parallel to one another. The etching channels are configured to be connected to a vertical access channel in the third functional layer.