In this thesis wire and arc additive manufacturing with a 15-5 PH martensitic stainless steel wire is researched. The problem is in finding the correct parameters which allow for a stable process and in finding relations and interactions between process parameters and measured control factors. With designed experiments the following was explored: a) influence of the wire stick out length on the welding voltage and current, b) influence of fine tuning pulse dynamics in pulse welding on weld bead geometry and ammount of spatter and c) influence of the welding current, voltage and weld interpass temperature on the geometry of welded layers and on the process stability. It was established that it is possible to correlate wire stick out length to the value of welding voltage and current. We established the relation between pulse dynamics parameters and amount of spatter during welding. We discovered the relation between process parameters and the geometry of the wire and arc additive manufactured layers of products. We manufactured a test product with optimized parameters for the most stable process and desired geometry of the layers.