The present invention is intended to provide a magnetic pole, a magnet apparatus, and a magnetic resonance imaging apparatus that the magnetic structure of the magnet apparatus for generating a uniform magnetic field is formed in a lower burst mode, and the profitability is increased, and at the same time, the uniformity of the magnetic field is improved. According to the present invention, the magnetic poles arranged opposite to each other across a measuring space have at least one of a plurality of hollows and a single hollow having a shape continuously changing on the section perpendicular to the direction of the magnetic field formed in the measuring space and particularly in order to make the magnetic field uniform, the arrangement of the plurality of hollows and the shape of the single hollow are adjusted. The magnet apparatus and magnetic resonance imaging apparatus of the present invention are structured as mentioned above.