CaF₂–P₂O₅–B₂O₃ glasses mixed with 0.2mol % of MnO were prepared. The prepared samples were exposed to γ-rays for doserate of 1.5kGy/h for two hours and their EPR spectra were recorded in the temperature range 300–475K. The spectra of pure as well as MnO doped glass samples exhibited a new and nearly axially symmetric(g_⊥=2.0085 and g_||=2.0090, A_⊥= 34 G and A_||= 52 G) signal with doublet hyper fine structure. The signal is attributed to  PO₄^2- radical formed by trapped hole on non-bonding orbital of oxygen. The analysis of these data together with thermoluminescence (TL) studies indicated that  PO₄^2- radical plays a crucial role in TL emission.