taper angle of 30 u00b0 to 70 u00b0 as shown in fig6 b the etching process of the bus electrode 4 b will be described in detail later a photosensitive insulating material is deposited and then patterned on the substrate 2 having the anode electrode 4 to thereby form a insulating film 6 as shown in fig6 c the insulating film 6 is formed in a lattice type at an entire portion except for a light emitting portion a photosensitive insulating material is deposited and then patterned on the substrate 2 having the insulating film 6 to thereby form a barrier rib 8 as shown in fig6 d the barrier rib 8 is formed with a predetermined distance from adjacent barrier ribs in a direction crossing the anode electrode 4 and is formed at a non light emitting portion an organic layer 10 is formed on the substrate having the barrier rib 8 as shown in fig6 e the organic layer 10 includes hole carrier layer a light emitting layer and an electron carrier layer a cathode electrode 12 is formed on the substrate 2 having the organic layer 10 as shown in fig6 f at this time the cathode electrode 12 is entirely deposited to be formed but is separated for each el cell by the barrier rib having a relatively high height to be formed meanwhile the bus electrode 4 b of the anode electrode according to the present invention is formed with result that a metal such as chrome cr molybdenum mo copper cu etc is etched by an anisotropic etching manner using an etchant consisted of compositions shown in table 1 at a temperature of a normal temperature to 45 u00b0 c preferably temperature of about 30 u00b0.