To enable rotary joint A including an electric signal slip ring 31 for exchanging different plural electric signals between a stationary body 1 and a rotating body 6 to transfer electric signals stably at the electric signal slip ring 31.

Stationary electrode layers 38a, 38b are layered between stationary electrodes 36b-36e composed of ring plates coaxial with the center of the stationary body insulated by stationary insulation sheets. Rotating electrode layers 42a-42c are provided between rotating electrodes 40a-40f composed of ring plates coaxial with the center of the rotating body insulated by rotating insulation sheets 41a-41c. Plural balls 44 are provided between the stationary electrodes and the rotating electrodes located side by side along the axis for exchanging electric signals between both the electrodes by rolling.