An electrophotographic printing device of modular construction with a support device, including a transport device, upon which a substrate may be transported between a start position and a target position and one or several electrophotographic units arranged on the support device, between the start and target position, having a developer unit, a photoconductor and an illumination unit for the photoconductor. The support device includes two or more housing positions arranged one behind the other in the transport direction of the transport device, provided with unitary mechanical interfaces. The electrophotographic units include unitary fixing pieces which are complementary in form to the interfaces. Such a printing device may be flexibly laid out due to the technical assembly thereof and may be individually set-up easily for specific printing jobs.