Structural steel is among the most widely used material in mechanical engineering. Due to the increasing geometric complexity of products, which precludes the use of conventional technologies, recent years have seen the development of additive manufacturing technologies that make the manufacture of such products practical. This thesis focuses on the research of shape-deposition wire-arc additive manufacturing using structural steel. The experiments were carried out using a CNC machine and a synergic power source. The samples were manufactured by a MIG/MAG welding process using a low spatter welding programme and G3Si1 welding wire of 1.2 mm diameter. Within the scope of this diploma thesis, we researched the effects of process parameters that facilitate the manufacture of quality walls. The results show that choosing appropriate welding parameters and interpass temperatures allows fabrication of walls of up to 9.11 mm thickness with a material utilisation rate of over 90 %. Walls manufactured in this thickness can be subsequently processed to yield thin-walled products of highly accurate shape.