The advances in terahertz technology drive the needs for the design and manufacture of waveguide devices that integrate complex 3D miniaturised components with meso and micro scale functional features and structures. Therefore, in parallel with the development of such terahertz devices it is necessary to design and validate new manufacturing platforms for their batch production. Especially, with the frequency increase the dimensions of the waveguide functional structures decrease and they are in the micro range from 200 µm to 50 µm with tight requirements for accuracy and surface integrity as they determine the devices' performance. In this context, this paper presents a novel manufacturing route for scale up production of terahertz components, which integrates Computer Numerical control (CNC) milling and laser micro-machining. A solution to overcome the resulting tapering of the laser ablated volumes while achieving a high accuracy and surface integrity of the machined structures is proposed in this research. In addition, an approach for two-side processing of waveguide structures within one laser machining setup is described that employs a higher precision alignment procedure. The capabilities of the proposed manufacturing route are demonstrated on a terahertz waveguide component that is functionally tested to assess the effects of the achieved dimensional accuracy and surface integrity on its performance. In particular, the resulting taper angle can be reduced to +/- 1° from its nominal value, while the dimensional accuracy of the produced structures is better than 10 µm. The results show that the proposed manufacturing solution can be a very promising alternative for the scale up production of terahertz components.