To provide a method of producing a cover glass for a portable device capable of printing directly on the surface of a glass substrate for a chemically-tempered cover glass, and preventing crack generation on the glass substrate upon printing.

This method of producing a cover glass used for a portable device includes a printing step for printing on the surface of the glass substrate for the cover glass. Before the printing step, a protection film 2 is formed on a region excluding a printing surface 1A of the glass substrate 1. For example, the protection film 2 is formed at least on a region of the glass substrate having a contact with a positioning member in a printer used in the printing step. Further, in the printing step, printing is applied onto the printing surface 1A of the glass substrate 1 in the state where the protection film 2 is formed.