The evaluation of fuel cell-stack costs was performed under the same conditions, in terms of hydrogen production rate, for both systems (450 Nm³/h). The stack cost of SOFC (equivalent to a stack for a 1.5 MW steam electrolyzer) was 8.5 JPY/W, while that of PEFC (equivalent to a stack for a 1.9 MW water electrolyzer) was 10.7 JPY/W. Hydrogen production costs were then evaluated using a solid oxide electrolysis cell (SOEC) and a polymer electrolyte membrane electrolysis cell (PEMEC). We assessed the hydrogen production costs for processes involving SOEC and PEMEC stacks, as well as compression and storage processes, and compared the SOEC cost with that of PEMEC. Finally, a technology scenario for hydrogen production was discussed and future technological challenges to achieving hydrogen production at a cost less than 5 JPY/MJ were proposed.