To provide a means for preventing a noise figure of RF signals from being deteriorated and to improve image quality of a magnetic resonance image.

Signal intensity of the RF signals outputted by an RF coil 4 is detected by a detection section 12 and a switching unit 22 installed between an attenuator 21 of an amplifying circuit 16 and an amplifier 23 is controlled by a control section 11 in accordance with the signal intensity of the RF signals. The amplifying circuit through which the RF signals pass is selected by a switching unit depending on whether the RF signal outputted by the attenuator 21 controlled by the control section 11 is outputted to an attenuator 24 of the amplifying circuit 17 or to an amplifier 25.