The heat-resistant Inconel 718 alloy, manufactured according to various modes of electron beam fusion, has been studied. The phase composition and microstructure features of the alloy in the initial state and after hardening heat treatment are analyzed. The fractures of alloy samples after uniaxial tensile tests were studied. It is established that the fracture of the material occurs by a ductile mechanism. However, there are a significant number of defects in the fractures in the form of non-molten areas and porosity, which is typical for products obtained by additive technologies from powder materials. It is shown that the fracture of the alloy is provoked by the presence of non-molten sections and intermetallic particles of the δ-phase in the structure.