NOVELTY - Manufacturing flat plate battery (100), comprises: providing chlorophyll layer (130), first and second separators absorbing solution of organic salt, and negative electrode layer (110); arranging the first separator absorbing the solution of organic salt on negative electrode layer; arranging the chlorophyll layer on first separator; arranging the second separator absorbing the solution of organic salt on the chlorophyll layer; arranging positive electrode layer on second separator; and sandwiching the chlorophyll layer, separators, electrode layers between the upper and lower plates.    USE - The method is useful for manufacturing a flat plate battery (claimed) which can store hydrogen to generate electricity.    ADVANTAGE - The method: is simple, economical and utilizes non-toxic substances which does not cause environmental pollution; and avoids the problems encountered during the manufacturing process of conventional batteries. The activated conductive polymeric layer enhances the electric supplying capability of the flat plate battery.    DETAILED DESCRIPTION - Manufacturing a flat plate battery, comprises: (a) providing a chlorophyll layer (130); (b) providing a first separator and a second separator absorbing a solution of organic salt; (c) providing a negative electrode layer (110); (d) arranging the first separator absorbing the solution of organic salt on the negative electrode layer; (e) arranging the chlorophyll layer on the first separator; (f) arranging the second separator absorbing the solution of organic salt on the chlorophyll layer; (g) arranging a positive electrode layer on the second separator; and (h) sandwiching the chlorophyll layer, the first separator, the second separator, the negative electrode layer and the positive electrode layer between an upper plate and a lower plate.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of the flat plate battery.    Flat plate battery (100)    Negative electrode layer (110)    Conductive layer (111)    Metal powder layer (112)    Chlorophyll layer (130)