Energy-dispersive x-ray spectroscopy is one of the indispensable methods for elemental analysis. Superconducting detectors can outperform the conventional semiconducting detectors in energy resolution and a coverage of x-ray photon energies. However, the smallness of superconducting detectors limits their applications to real analyzing tools. We have found by using spatially-resolved measurement with synchrotron radiation that the detector size can be increased by changing the structure of superconducting electrodes. The finding resulted in the superiority of the superconducting detector to the semiconducting detector as shown in the figure, and thus opens the possibility of real analyzing tools.