To improve the radio-frequency properties of radio-frequency substrates or radio-frequency conductor arrangements, the invention proposes a glass material for producing insulation layers for radio-frequency substrates or radio-frequency conductor arrangements, which, as an applied layer, in particular with a layer thickness in the range between 0.05 .mu.m and 5 mm, has a loss factor tan .delta. of less than or equal to 70*10.sup.-4 in at least a frequency range above 1 GHz.