There is provided an RF coil capable of resonating or tuning two frequencies, having uniform spatial sensitivity and having a small spatially occupied volume, especially an RF coil suitable for a high magnetic field MRI apparatus. A coil apparatus is made up of a plurality of linear conductors 200, 201 arranged around a central axis and two ring conductors 202, 203 connected to the respective ends of the plurality of linear conductors 200, 201 and capacitors are inserted in the linear conductors 200, 201 and ring conductors 202, 203. The plurality of linear conductors are made up of conductors 200 located near the central axis and conductors 201 located far from the central axis and the ring conductors 202, 203 have star-like polygonal shape so that the linear conductors are arranged alternately. This structure can realize two tuning modes; a resonance mode similar to a birdcage type resonance mode and a resonance mode which becomes zero (node) in the vicinity of the linear conductor group 200 located near the central axis.