A new computation method of grain boundary energies for arbitrary misorientation and inclination angles has been proposed, based on an atomistic approach (molecular statics) using a semi-empirical atomic potential (2NN MEAM). The procedure was applied to computation of [110] symmetric tilt boundary energy of pure Al. It will be shown that the computed grain boundary energy and especially its misorientation dependency are in good agreement with experimental literature information. The probable sources and amounts of computation error, and the applicability to computation of inter-phase interface boundary energy will also be discussed.