PURPOSE: To omit a process for making a sheet and realize high performance by using an amorphous carbon film having a low degree of orientation.

CONSTITUTION: A fire resisting treatment is applied to a polyacrylonitrile film composed of acrylonitrile and methacrylic acid at a predetermined temperature under tension where free contraction is restrained in the atmosphere. The film is baked at a high temperature under non-tension in the presence of nitrogen, thus obtaining an amorphous carbon film. A carbon film electrode is constituted of the carbon film, to be used as a negative electrode. A positive electrode slurry is prepared by mixing LiCoO2, artificial graphite and polyvinylidene in a predetermined ratio, followed by applying on an aluminum foil, drying and pressing, thereby obtaining a positive electrode. A porous polypropylene film is used as a separator, and propylene carbonate including lithium perchlorate is used as an electrolyte. With this arrangement, a secondary battery can be provided. A baking temperature for obtaining the carbon film is preferably set to 900-1500°C.