A method of producing a glass substrate having a first layer formed on a surface of the substrate by low-temperature CVD includes preparing the glass substrate and forming the first layer on the glass substrate by the low-temperature CVD. In the glass substrate after forming the first layer, an integrated value after a baseline correction in a wavenumber range of 2600 cm−1 to 3800 cm−1 in a peak due to OH groups obtained by an FTIR measurement on the first layer is 9.0 or less, and the C content of the first layer is 1.64 at % or less.