In a method for manufacturing a micromechanical device having a region for forming an integrated circuit, at first a first layer is produced on a deeper-lying part in the substrate. Subsequently, a membrane layer is produced on the first layer and at least one channel completely penetrating the membrane layer is introduced in the membrane layer. After that, a region of the first layer below the membrane layer is removed to form a cavity. Finally, the channel is sealed and a planar surface is formed.