Disclosed is a movable portion transmission system including a primary transmission power supply 1 to supply electric power, a transmitter and receiver 3 configured with a transmission antenna 5 to perform wireless transmission of the electric power supplied thereto, and a reception antenna 6 to receive the electric power from the transmission antenna 5 with which the reception antenna pairs up, a transmission power supply circuit 2 to establish a resonance condition of the transmission antenna 5 with which the transmission power supply circuit pairs up, and a reception power supply circuit 4 to establish a resonance condition of the reception antenna 6 with which the reception power supply circuit pairs up, in which the transmission antenna 5 includes a transmission side coil 7 in a spiral shape which is arranged while being centered at the axial center of a rotary member and the reception antenna 6 includes a reception side coil 8 in a spiral shape which is arranged with a gap therefrom to the transmission side coil 7 while being centered at the axial center of the rotary member.