Non-weldable materials such as various Ni-based superalloys exhibit high thermo-mechanical properties as well as a good corrosion resistance at high temperatures [1]. However, the advantages of additive manufacturing processes are not yet profited for difficult and non-weldable alloys due to their poor weldability [2-4]. Thus, in this paper, fused filament fabrication (FFF) is applied for manufacturing complex components from non-weldable Ni-based superalloy. For this purpose, the alloy MAR-m247 is investigated. The elimination of the high cracking susceptibility of MAR-m247 during filament fabrication and sinter-based FFF process will be highlighted. The fabrication of highly filled filaments with 94 wt.% of metal is described. The effects of process parameters, debinding and sintering on the tensile strength and fatigue behavior at room and high temperatures are discussed. The microstructure of the sintered specimens after post-heat treatment was investigated by electron microscopy. The porosity in the sintered specimens is less than 2%, while the total shrinkage is about 14 %.