[en] This text contains the following subjects. (1) Introduction, (2) Positioning of RF source in International Linear Collider (ILC), (3) Outline of RF source in ILC500, (4) RF source for main linac, (4-1) RF scheme of main linac, (4-2) Difference between RF sources for TESLA and ILC500, (4-3) Cost reduction of RF source and Alternative Configuration Design (ACD), (4-4) Klystron, (4-5) Modulator, (4-6) Power distribution system (PDS), (5) Outline of RF sources other than those for main linac, (5-1) RF source in electron source, (5-2) RF source in positron source, (5-3) RF source in Ring to Main Linac (RTML), (5-4) RF source in Damping Ring (DR), (5-5) RF source in Beam Delivery System (BDS), (6) Summary, (APPENDIX 1) Perveance and efficiency of klystron, and (APPENDIX 2) Outline of components of power distribution system. (K.Y.)