In a power transmitting device (101) and a power receiving device (201), active electrodes (13, 23), passive electrodes (14, 24), and reference potential electrodes (15, 25) oppose each other so as to make capacitance coupling, so that capacitances Caa, Cpp, and Cgg are generated. Capacitors having capacitances C1a, C1p, C2a, and C2p are connected to between the reference potential electrode (15) and the active electrode (13), between the reference potential electrode (15) and the passive electrode (14), between the reference potential electrode (25) and the active electrode (23), and between the reference potential electrode (25) and the passive electrode (24), respectively. The power transmission system (1) satisfies any one or more of the conditions of Caa+Cpp