The present invention provides a technique that makes it possible to adjust resonance frequency without sacrificing test space in a high-frequency coil of a of a tunnel-type MRI apparatus. The present invention provides a high-frequency coil of a tunnel-type MRI apparatus that forms a resonant loop for determining the resonance frequency of the high-frequency coil from a high-frequency shield and a coil pattern, the tunnel-type MRI apparatus being equipped with a cylindrical high-frequency shield, a coil pattern placed on a cylindrical virtual plane having the same central axis as the high-frequency shield, and a frequency adjustment unit. The frequency adjustment unit is placed between the high-frequency shield and the coil pattern so as to be able to adjust the coupling capacitance therebetween, thereby making it possible to adjust the resonance frequency of the resonant loop.