Surface morphology and charge/discharge characteristic in a 5×5 μm2 area of an all-solid-state Li secondary battery (Al/Li/SiO2–15 at. %P2O5/LiMn2O4/polycrystalline silicon) embedded in a Si substrate are simultaneously observed by atomic force microscopy with a conductive probe. The battery area of 5×5 μm2 shows charge/discharge behavior corresponding to the movement of ∼2.9×1010 Li+ ions/μm2, reflecting the cyclic movement of Li+ ions. The Al electrode consisting of scale-shaped grains of 0.1–1.5 μm in size rises by ∼30 nm during the first charge operation. The surface of the Al electrode shows a cyclic change from scaly to wrinkled structures with the charge/discharge operations, indicating the drawing of the excess Li in the anode into the glassy electrolyte. These results are promising for the realization of a micrometer-sized battery. © 2004 American Institute of Physics.