[en] The fundamental characteristics of electron beam melting of low-melting point metals such as aluminum alloy were studied utilizing a prototype of a beam oscillation pattern input system which allows the electron beam to be freely controlled. Observations on the melting phenomena of a specimen of aluminum alloy were made at various beam currents, beam scanning frequencies and beam oscillation patterns. The optimum melting conditions, with a constant capacity evacuation system, were a beam scanning frequency of approximately 10 Hz, at which the quantity of metal vapor generated per unit time was small, and a beam output no higher than the level at which the beam penetrates the specimen. To apply the beam energy as effectively as possible, the molten surface should not be repeatedly scanned and the oscillation pattern should not result in heating the molten pool. (author)