An object of the present invention is to provide a fuel cell preventing formation of a diffusion layer containing Ca and other elements, and having an excellent power generation performance at low temperature by preventing breakdown of a crystal structure of an electrolyte by firing. The process has the ability to control properties, such as particle size, of the raw pigment produced. Alternatively, the array may comprise semiconductor pillars with different linewidths, optionally within the context of the foregoing linewidth and separation distance limitations. 01 to 1 unit and hence is a method with a high sensitivity, reproducibility and accuracy.