Electron spin resonance (ESR) images were obtained by scanning samples over an aperture of a microwave cavity. A spatial resolution of 0.2 mm, which is below both the wavelength of the electromagnetic wave ( ~ 3 cm) and the diameter of the aperature (1mm), was obtained by using a deconvolution algorithm. Resolution os three dots within a 1 mm diameter was demonstrated using a test sample. Microscopic images of spin concentration of Gd ³⁺ impurity before and after deconvolution are shown using a natural single crystal of zircon (ZrSiO₄) with a zonal structure. ESR images of Jurrasic carbonate fossils of crinoid and ammonite are shown.