To improve a self-resonance frequency of an RF coil.

An RF coil for detecting a nuclear magnetic resonance phenomenon includes: two guard rings disposed separated from each other in an axial direction; and first and second vertical band sections having an almost linear shape extended in the axial direction, the first and second vertical band sections being disposed opposite to each other. The structure of the vertical band sections is (1) a straight type in which both band sections have an almost linear shape or tapered shape, (2) a straight type in which both band sections have an almost linear shape or tapered shape and a separate wing type in which separate wing sections are disposed separated from each other between both vertical bands, and (3) an asymmetrical wing type in which one of the vertical band sections has an almost linear shape or tapered shape, and the other vertical band section has wing sections protruding to one vertical band section along the guard rings.