Glassy and glassy-crystalline silver ion conductors of the AgI–Ag2O–P2O5 system have been studied by FTIR-PAS and Micro Raman spectroscopies in conjunction with X-ray diffractometry, scanning electron microscopy and differential scanning calorimetry. It was found out that materials with lower (≤60mol%) AgI contents are fully amorphous, while those with higher contents of AgI (>70mol%) contain crystalline grains of β/γ-AgI embedded in the glassy matrix. Annealing of the glasses at 105°C and/or 145°C resulted in an increase in the formation of a yet unidentified crystalline phase dispersed in the glass. From the spectroscopic studies it was found that PO4 3− units existed as separated species in the glass network or precipitated crystalline phases regardless the thermal treatment of the material. Vibrations of PO4 3− units appeared to be affected by the total concentration of AgI and microstructure. The spectroscopic methods were also used to study crystallization process in the glassy samples.