To provide an MRI apparatus capable of cooling a gradient magnetic field power source and a gradient magnetic field coil depending on a sequence.

The MRI apparatus includes: a cooling unit 107 which water-cools a gradient magnetic field generation system by setting target command values of the quantity of water and a water flow; a temperature sensor 105b which detects the quantity of water, the water flow and the temperature of the cooling unit; and a sequencer 4 which sets and controls the target command values of the quantity of water and the water flow on the basis of a sequence command value imparted into each axis of the gradient magnetic field generation system, with respect to the quantity of water, the water flow and the temperature of the cooling unit, detected by a detector.