Solid Oxide Fuel Cell (SOFC) has several non-replaceable advantages over the others, e.g. the issues of high volumetric power density and low cost. Those advantages have been appreciated in recent developments, and implemented in several micro-SOFC devices conducted by several international projects. ONEBAT System by ETH (with 4 other groups) in Switzerland, micro-tubular SOFC by AIST in Japan, micro-honeycomb fuel cell (FC) by Professor Ishihara at Kyushu University will be reviewed in this report. Some micro-devices have been built on Si-chip, or in associated with the accessory parts, such as fuel reformer, electric power collector, or micro-turbine. Those have demonstrated important technology breakthrough and also shown the potential for commercial applications. This report will also discuss two important issues, including gas transport limitation in small gaps and glass sealing for the practical applications of Micro-SOFCs.