Mass spectra of (GeS2)50(Sb2S3)50 glass and Ag-doped glasses [5% Ag (GeS2)50(Sb2S3)50 and 15% Ag (GeS2)50(Sb2S3)50] obtained using laser desorption ionization (LDI) time-of-flight coupled with quadrupole ion trap mass spectrometry were studied. The analysis of the mass spectra indicated the formation of AgaGebSbcSd clusters. In addition to the SbSd+ (d = 1 and 2), Sb2Sd+ (d = 1–3), Sb3Sd+ (d = 1–5), Sb4Sd+ (d = 3 and 4), Sb5S2+, and Sbc+ (c = 3 and 5) clusters, various clusters containing Ag, such as Aga+ (a = 1 and 2), AgGeS+, AgSbc+ (c = 1, 2, and 4), AgSbS+, AgSb2Sd+ (d = 1–5), AgSb3S3+, AgSb4S4+, Ag2Sb3Sd+ (d = 4 and 5), Ag4Sb2S3+, and Ag5SbS3+, were generated. Moreover, in spite of the five-ninth purity of all glass components, several hydrogenated clusters (SbS3H8+, Sb4S2H+, Ag2H11+, Ag2Sb3H4+, Ag3Sb2H4+, Ag4Sb2H2+, and Ag4S3H8+) and some low-intensity oxidized clusters, such as Sb3O+ and Sb3O5+, were also detected. When applying LDI on (GeS2)50(Sb2S3)50 glass, no Ge-containing clusters were detected in the positive ion mode, and just one Ge-containing cluster was observed after doping the glass with Ag. Hydrogen plays an important role in the glasses studied. The knowledge gained concerning cluster stoichiometry contributes to the elucidation of the structure of Ag-doped Ge–Sb–S chalcogenide glasses. It should be noted that some of the clusters were considered to be structural fragments. Furthermore, mass spectrometry was complemented with Raman spectroscopy.