To provide an identification mark imparting method capable of imparting an identification mark by an inexpensive system and free of adverse effects on manufacturing environment.

A method of manufacturing an organic EL panel includes sticking together an organic EL element substrate having organic EL elements formed successively on a continuous base substrate and a sealing member having an adhesive layer formed on a continuous sealing substrate. Identification marks are printed in advance on either of the sealing substrate or the base substrate at printing intervals shorter than arrangement intervals of the organic EL elements, and at least one identification mark is imparted to each of the cut organic EL panels.