PURPOSE: To make power generating elements thin to manufacture a thin flat- type battery by spreading paste-form active material prepared by mixing with electrolyte on a positive current collector, and embedding a desired number of plate-shaped or fine rod-form negative electrodes in the positive current collector with a separator placed between them.

CONSTITUTION: Ag2O serving as active material, graphite serving as conductor, and NaOH solution are kneaded and spreaded on a metal plate current collector 5 to form a positive electrode 4. A separator 3 is placed on the positive electrode 4 and impregnated with electrolyte, and a desired number of plate-shaped or fine rod-form negative electrodes 2 are placed thereon, then embedded with the separator 3 into the positive electrode layer by applying pressure. The separator 3 and negative zinc 2 are formed longer than the positive layer 4 coated on the positive current collector, and bent to the positive electrode side, and a negative current collector 1 is placed thereon. The positive current collector 5 is melt-bonded to an outer jacket 6, and the negative current collector 1 serving as a terminal is also covered with an outer jacket film, then the negative side jacket film is melt-bonded with the positive side jacket film to seal a power generating elements.