Retaining assembly for an electrostatic atomizer, in particular a rotary atomizer, which extends along a system longitudinal axis with a first coupling plate arranged in an installation position proximally in relation to a device carrying the retaining assembly, wherein the first coupling plate defines a first coupling plate plane extending transversely to the system longitudinal axis, is configured for connection to a robot or other similar automatic handling unit, has at least one first coupling piece of a fluid coupling and a first plug element of an electrical plug, the retaining assembly further comprises a second coupling plate, which is configured to be complementary to the first coupling plate, which is arranged in an installation position distally in relation to the device carrying the retaining assembly, which defines a second coupling plate plane extending transversely to the system longitudinal axis, on which a base plate spacing the rotary atomiser distally from the second coupling plate plane is provided for carrying the rotary atomizer, which has at least one second coupling piece of the fluid coupling that is configured to be complementary to the first coupling piece and can be plugged thereinto, and a second plug element of the electrical plug that is complementary to the first plug element and can be plugged thereinto, wherein the coupling plates are releasably connectable to one another via a coupling element for fixing in an installation position in relation to one another, in which the coupling pieces (8a, 10a) of the at least one fluid coupling are connected to one another in a fluid-tight and fluid-conducting manner and plug elements of the electrical plug are connected to one another in an electrically conductive manner, wherein position-fixing means are configured between the coupling plates (8, 10), wherein the first and second plug elements are each arranged coaxially to form a central plug assembly with two complementary central plug elements, CHARACTERISED IN THAT the central longitudinal axis of the two complementary connector elements extends coaxially to the system longitudinal axis, IN THAT the central connector elements accommodate the connecting conductor lines within themselves, IN THAT the coupling element connecting the coupling plates (8, 10) to each other in the installation position comprises pulling/pushing means which engage and disengage the coupling plates (8, 10) by performing a translational movement, IN THAT the pulling/pushing means comprise at least one pull rod (26, 28) on a coupling plate, which pull rod passes through one or more complementary through-hole(s) (38, 40) on the other, complementary coupling plate and IN THAT the pulling/pushing means comprise a pulling collar (30,32) at a distal end that projects radially beyond the outer surface of the pull rod. in which the coupling pieces (8a, 10a) of the at least one fluid coupling are connected to one another in a fluid-tight and fluid-conducting manner and plug elements of the electrical plug are connected to one another in an electrically conductive manner, wherein position-fixing means are configured between the coupling plates (8, 10), wherein the first and second plug elements are each arranged coaxially to form a central plug assembly with two complementary central plug elements, CHARACTERISED IN THAT the central longitudinal axis of the two complementary connector elements extends coaxially to the system longitudinal axis, IN THAT the central connector elements accommodate the connecting conductor lines within themselves, IN THAT the coupling element connecting the coupling plates (8, 10) to each other in the installation position comprises pulling/pushing means which engage and disengage the coupling plates (8, 10) by performing a translational movement, IN THAT the pulling/pushing means comprise at least one pull rod (26, 28) on a coupling plate, which pull rod passes through one or more complementary through-hole(s) (38, 40) on the other, complementary coupling plate and IN THAT the pulling/pushing means comprise a pulling collar (30,32) at a distal end that projects radially beyond the outer surface of the pull rod.