Worldwide, an increasing number of projects have been implemented that use biomass discarded as waste—designated biomass waste in this chapter—as a renewable resource. Such projects, called biomass projects, involve various parties, including municipalities, private companies, consortia, and NGOs. The purpose of this chapter is to clarify the optimal organizational form of a biomass project. To begin, we survey examples of biomass projects in Japan to identify their typical features. Given that biomass projects have both public and commercial aspects, we are concerned with public-private partnership (PPP) as an organizational form for biomass projects. To examine the applicability of PPP to a biomass project, we review previous studies of PPP in the economics literature. The results are mixed: PPP is preferable under some conditions but not appropriate under others. These findings might be attributable to the method employed: the literature reviewed is only concerned with the contractual aspect of PPP, and our discussion is somewhat subjective. It may be useful for future research to take a different approach, recognizing that participants in a biomass project are all concerned with the affairs of the region and will thus collaborate on the project beyond making profits.