A magnetic resonance imaging apparatus comprises: static magnetic field generation means which generates a static magnetic field in an imaging space where an object to be examined is placed gradient magnetic field generation means which generates a gradient magnetic field in the imaging space high-frequency magnetic field generation means which generates a high-frequency magnetic field in the imaging space calculation means which calculates an amount of the electromagnetic wave absorbed by the object when the high-frequency magnetic field is irradiated to the object and a measurement means which measures a characteristic of the high-frequency magnetic field generation means. The calculation means calculates the amount of the electromagnetic wave absorbed by the object according to the characteristic of the high-frequency magnetic field generation means measured by the measurement means.
