The purpose of this paper is to validate plan of R&D on solar-cells in the (New-) Sunshine Program of Japan by using cost-effectiveness analysis and to demonstrate usefulness of the analysis for R&D planning. Based on the analysis, R&D goals and/or allocation of R&D expenditure of multicrystalline silicon (mc-Si) might not be appropriate after FY1996. And R&D expenditure for solar cells might be decided without forecasting increase of the mc-Si solar cell production by the subsidization programs. (C) 2002 Elsevier Science B.V. All rights reserved.