SPM sensor comprising a holding element, cantilever and a sensor tip, which projects out of the surface of the cantilever, at the free end of the cantilever, at least the cantilever and the three-surface sensor tip consisting of monocrystalline -silicon, and a process for producing this sensor. A correction value computing unit determines correction values used to correct dequantized values in a dequantizer in accordance with the number of quantization indices decoded by the entropy decoder. 5+2y, wherein Re is Y, La, a Lanthanoid series element, or a combination thereof, A is, 0. A solvent of the electrolytic solution contains a given sulfone compound such as bis-2,2-difluorosulfoacetate.