A glaze composition suitable for a thin chip substrate, for example. The glaze composition makes a low-temperature glazing possible and is superior in the electrical and chemical stability. The glaze composition can prevent even a thin substrate from warping and can easily form an extensive smooth glaze layer without deteriorating a thin glaze face. The components of the composition are 20% to 50% by weight of boron oxide, 5% to 35% by weight of aluminum oxide, and 15% to 55% by weight of at least one alkaline-earth oxide selected from the group consisting of calcium oxide, strontium oxide, magnesium oxide and barium oxide.