In this work we succeeded in synthesizing a chalcogenide glass, that is, the Ag3PS4 glass, by milling the mixture of the crystalline Ag2S and P2S5 powder. In terms of potential energy, the glass was excited by the milling process. The evidence for the energy excitation was the occurrence of the sub-T-g relaxation recorded by a differential scanning calorimeter (DSC). The relaxation behavior in the milling-derived Ag3PS4 glass was found to significantly differ from that of a hyperquenched oxide glass. We observed two decoupled peaks of the energy release during a DSC scan, which are in contrast to the single asymmetric peak of the hyperquenched glass. The low-temperature peak could be attributed to the -relaxation of the Ag-S ionic bonds, whereas the high-temperature peak could arise from the -relaxation of the distorted rigid [PS4] units involving covalent bonds. The decoupling between the two peaks implies the fragile nature of the Ag3PS4 glass. Upon the dynamic heating and the sub-T-g annealing we found that the relaxation of the Ag3PS4 glass is of high nonexponentiallity, and hence, of high structural heterogeneity.