NOVELTY - An alkali-free glass contains (in mol%) silica (66-70), alumina (12-15), boron oxide (0-1.5), magnesium oxide (6-9.5), calcium oxide (4.5-8), strontium oxide (2-7), barium oxide (0 or more to 1) and zirconia (0-2). The alkali-free glass has strain point of 725 degrees C or more, average thermal expansion coefficient at 50-300 degrees C of 30-40x 10-7/ degrees C, temperature at which glass viscosity is 102 dPa.second of 1710 degrees C or less, temperature at which glass viscosity is 104 dPa.second of 3330 degrees C or less and glass surface devitrification temperature of 1330 degrees C or less.    USE - Alkali-free glass is used for manufacturing glass plate (claimed) for display board, substrate for photomask and substrate for solar cell.    ADVANTAGE - The alkali-free glass has high strain point, low viscosity and low devitrification property.    DETAILED DESCRIPTION - An alkali-free glass contains (in mol%) silica (66-70), alumina (12-15), boron oxide (0-1.5), magnesium oxide (6-9.5), calcium oxide (4.5-8), strontium oxide (2-7), barium oxide (0 or more to 1) and zirconia (0-2). The sum total content of magnesium oxide, calcium oxide, strontium oxide and barium oxide in the alkali-free glass is 14-18.2. The ratio of content of magnesium oxide and sum total content of magnesium oxide, calcium oxide, strontium oxide and barium oxide in the alkali-free glass is 0.35 or more. The ratio of content of magnesium oxide and sum total content of magnesium oxide and calcium oxide in the alkali-free glass is 0.52 or more. The ratio of content of magnesium oxide and sum total content of magnesium oxide and strontium oxide in the alkali-free glass is 0.45 or more. The alkali-free glass has strain point of 725 degrees C or more, average thermal expansion coefficient at 50-300 degrees C of 30-40x 10-7/ degrees C, temperature at which glass viscosity is 102 dPa.second of 1710 degrees C or less, temperature at which glass viscosity is 104 dPa.second of 3330 degrees C or less, glass surface devitrification temperature of 1330 degrees C or less, and glass inside devitrification temperature of 1330 degrees C or less. INDEPENDENT CLAIMS are included for the following:    (1) manufacture of glass plate; and    (2) manufacture of alkali-free glass.