In one embodiment, an MRI apparatus includes: a transmission circuit configured to apply a transmission pulse to an object; at least one radio frequency (RF) coil configured to include an active trap circuit provided with a PIN diode, and to receive a magnetic resonance signal from the object; a power supply circuit configured to apply a reverse bias voltage and a forward bias voltage to the PIN diode, and to apply multiple values of a forward current when the forward bias voltage is applied to the PIN diode; and a control circuit configured to control the power supply circuit in such a manner that the power supply circuit sets the forward current to the multiple values, depending on imaging conditions.