An inverter for an electric motor , - wherein the inverter comprises a capacitor plate comprising several capacitors , several transistor plates each comprising several transistors , a cooling plate , and a control board , - wherein the inverter comprises a hollow cylindrical carrier comprising a central axis , - wherein the control board , the capacitor plate , the respective transistor plates , and the cooling plate are located axially one on top of the other, - wherein the control board , the capacitor plate , and the respective transistor plates are electrically interconnected, - wherein the cooling plate closes axially the carrier , which receives and supports the capacitor plate , the transistor plates , and the control board , and encases them in the circumferential direction to the outside, characterized in - that the inverter forms a cohesive and fully assembled and assembly-ready for assembling on the electric motor assembly unit with the carrier , the capacitor plate , the transistor plates , the cooling plate and the control board , - that a ring-shaped carrier ring , which is aligned transversely to the central axis , is integrally molded in the carrier , and - that the carrier ring divides an interior of the carrier into two axially adjacent areas, wherein the transistor plates are received and secured in the first area, and the capacitor plate and the control board are received and secured in the second axial area, and - that the transistor plates are circumferentially distributed on the ring-shaped carrier ring around the central axis and are fastened to the carrier ring in a non-positive manner. - wherein the inverter comprises a capacitor plate comprising several capacitors , several transistor plates each comprising several transistors , a cooling plate , and a control board , - wherein the inverter comprises a hollow cylindrical carrier comprising a central axis , - wherein the control board , the capacitor plate , the respective transistor plates , and the cooling plate are located axially one on top of the other, - wherein the control board , the capacitor plate , and the respective transistor plates are electrically interconnected, - wherein the cooling plate closes axially the carrier , which receives and supports the capacitor plate , the transistor plates , and the control board , and encases them in the circumferential direction to the outside, - that the inverter forms a cohesive and fully assembled and assembly-ready for assembling on the electric motor assembly unit with the carrier , the capacitor plate , the transistor plates , the cooling plate and the control board , - that a ring-shaped carrier ring , which is aligned transversely to the central axis , is integrally molded in the carrier , and - that the carrier ring divides an interior of the carrier into two axially adjacent areas, wherein the transistor plates are received and secured in the first area, and the capacitor plate and the control board are received and secured in the second axial area, and - that the transistor plates are circumferentially distributed on the ring-shaped carrier ring around the central axis and are fastened to the carrier ring in a non-positive manner. <EOS>