Disclosed is a scale-like glass (10) having improved heat resistance and improved chemical durability, which is composed of a glass base material satisfying, as expressed in mass%, 65<；SiO 2 ‰¤70, 5‰¤Al 2 O 3 ‰¤15, 1‰¤MgO‰¤10, 10‰¤CaO‰¤25 and 0.1‰¤(Li 2 O+Na 2 O+K 2 O)‰¤4. The temperature difference ”T obtained by taking the devitrification temperature of the glass base material from the working temperature thereof is preferably within the range of 0°C to 200°C. The glass transition temperature of the glass base material is preferably within the range of 580°C to 800°C. Furthermore, it is desirable that the value of ”W, which serves as an index for the acid resistance of the glass base material forming the scale-like glass (10), is within the range of 0.05 to 0.8 mass%.
