To facilitate manufacturing while minimizing deflection. Provided is a glass 10 in which a parameter A is 0.817 or less, a parameter B is 0.898 or more, a ratio of a content of MgO to a total content of a divalent oxide RO is 0.65 or more in terms of mol % on an oxide basis, a Young's modulus is 80 GPa or more, and the glass is an alkali-free glass.