A magnetic resonance imaging apparatus includes a applying unit which applies a gradient magnetic field and a radio-frequency pulse to a subject placed in a static magnetic field, a radio-frequency coil unit which includes element coils to respectively detect magnetic resonance signals emitted from the subject, and outputs signals of a plurality of channels based on the magnetic resonance signals, receiving circuits each of which receives one of the signals of the plurality of channels, and whose number is smaller than the channels, a selecting circuit which includes matrix switches connected in multiple stages, selects some of magnetic resonance signals from the signals of the channels, and inputs the selected magnetic resonance signals to the receiving circuits, a setting unit which sets diagnostic conditions, and a determining unit which determines a connection state of the matrix switches in accordance with the set diagnostic conditions.