To obtain a glass material having a high dielectric constant and a reduced dielectric loss, and contains a low alkali component, and suitable for a substrate for an electronic circuit and a dielectric material such as a high frequency circuit element and a flat panel-display.

The glass has a composition containing, by mass, 5 to 25% P2O5, 0 to 15% B2O3, 0 to 5% SiO2+GeO2, 21 to 50% BaO+SrO, 0 to 3% Li2O+ Na2O+K2O and 35 to 65% Nb2O5, substantially containing no PbO components, and satisfying Nb2O5/(BaO+SrO)=0.85 to 2.20. The glass has a dielectric constant of ≥15, a dielectric loss of ≤10.0×10-4 and an electrical resistivity of ≥1.0×1016 Ω cm.