To provide a manufacturing method of an organic EL panel capable of improving light emission efficiency of an organic EL element.

This is the manufacturing method of the organic EL panel composed by sequentially laminating on a translucent supporting substrate 8, a transparent electrode 30 formed in a prescribed shape, an organic layer 32 having respective layers which are a positive hole injection layer, a positive hole transportation layer, a light emitting layer, an electron transportation layer, and a non-translucent rear face electrode 33, and it includes a process of preparing a vapor deposition device A provided with a plurality of vapor disposition rooms a2 to a5, b1 to b4 corresponding to the organic layer 32 and the rear face electrode 33 so as to film-form the organic layer 32 and the rear face electrode 33 on the supporting substrate 8 in which the transparent electrode 30 is formed, and includes a process of carrying out measurement of photoelectron emitting characteristics on the surfaces of the respective layer and on the surface of the rear face electrode 33 in the plurality of vapor disposition rooms a2 to a5, b1 to b4 after forming the respective layers and after forming the rear face electrode 33.