A method of filling a multilayered cell with media. In the method, a multilayered cell having at least two layers, i.e., a first and second layer, is filled with media. The method comprises forming in the first layer a first medium injection region for filling the first layer with a first medium, forming in the second layer a second medium injection region for filling the second layer with a second medium, the second medium injection region corresponding to a region different from the first medium injection region, superposing the first and second layers, forming within the first medium injection region a first through-hole extending through the multilayered cell in the layer-thickness direction, forming within the second medium injection region a second through-hole extending through the multilayered cell in the layer-thickness direction, and injecting the first and second media into the first and second through-holes, respectively, to fill the first and second layers with the first and second media. Thus, a multilayered cell can be easily produced in a shorter time while attaining a reduction in deterioration during production.