Since ca. 70% of the land in Japan is covered in forest, Japan has an abundance of woody biomass. However, the utilization of woody biomass for energy has not progressed that much. The reason for this is that the total cost of woody biomass production is relatively high, and also the supply and demand systems for energy use are not fully established. It is thus necessary to considerably reduce the total cost of woody biomass production. In this report, we have described a detailed bottom-up approach for evaluation of woody biomass production costs; we assessed the cost by considering a series of production processes from site preparation to tree trimming. Focusing on planted forests, we analyzed the costs in terms of region, slope angle and forestry machinery. The quantitative evaluation showed that the volume and slope angle of forest significantly influences the total production cost of woody biomass. Based on these results, the total production cost of woody biomass by region and topography was clarified by the application of various cost reduction methods. For forests on a gentle slope, it appears that it is possible to reduce by about one third the current costs through adoption of a combination of existing measures.