Method of manufacturing a substrate for organic electroluminescent device

a Disclosed is a method of manufacturing a substrate for an organic EL device, the method comprising the step of: filling grooves of the optical element with sol-gel coating solution or organic metal cracking solution when a diffraction grating is formed on the glass substrate , wherein an encapsulation member is mounted to the glass substrate in order to fill the groove with the coating solution, and the coating solution is injected into a gap between the encapsulation member and the diffraction grating , so that the organic EL device can be stably manufactured with low variation between optical properties according to positions of the substrate and with improved luminous efficiency. Further, the present invention provides a method of manufacturing a substrate for an organic EL device having a glass substrate with an diffraction grating , wherein the dispersion solution of particles is applied to the glass substrate to form the diffraction grating , so that the organic EL device can be stably manufactured with low variation between the optical properties according to the positions of the substrate and with the improved luminous efficiency.