In an MRI apparatus, RF shimming is performed with high precision in a short time irrespective of an object and an imaging mode. A database storing the shim parameter according to a change from a criterion state in advance is included when a state in which an shim parameter is calculated is set as the criterion state of the objet in order to obtain a high-quality image. At the time of imaging, the shim parameter registered in the database in association with a change amount closest to a change amount from the criterion state is used. In the database, the shim parameter calculated from a previously measured result is registered.
