We have developed a batch fabrication method of small cantilevers formed by crystal facets of single-crystal silicon for improving the sensitivity of atomic force microscopy. In order to realize a small cantilever with a very sharp tip, we have employed KOH anisotropic etching and local oxidation of silicon. We have made two types of small cantilevers, the V-shaped triangular type and the bulk triangular type. The length of each cantilever is 20 microm. The tip of the V-shaped type is bridged by two wires with thickness of 0.6 mum. The bulk triangular type has a thickness of 1.5 microm. The frequency characteristics of the cantilevers vibrated using photothermal excitation were measured by laser Doppler velocimetry. The resonance frequency of the V-shaped type and the bulk triangular type were 687 kHz and 8.42 MHz, and their spring constants are estimated to be 0.7 N/m and 370 N/m, respectively.