The present invention discloses an actuating unit for an electromechanically operable disc brake for automotive vehicles which is generally comprised of a drive unit or an electric motor, an actuating element, by means of which one of two friction linings that are slidably arranged in a brake caliper is moved into engagement with a brake disc, as well as a first and a second reduction gear. In order to uncouple the second reduction gear from the first reduction gear, it is disclosed in the present invention that the electric motor, the first reduction gear, and the second reduction gear are configured as at least two assemblies which can be handled independently.