PURPOSE: To provide a processor for a magnetic resonance signal which enables the picking up of a magnetic resonance signal with limited noise from a multicoil detector while allowing the realization of high resolutions.

CONSTITUTION: This processor is provided with an input mixer means which performs a frequency shifting of magnetic resonance signals to a second frequency band from a first frequency band, a bandpass filter means controllable to perform a bandpass filter processing of outputs from the input mixer means and an output mixer means which performs a frequency shifting of magnetic resonance signals from the controllable bandpass filter means to the first frequency band from the second frequency band. Also included are an adder 142 which couples signals from the output mixer means to generate an output signal of a low noise, an up/down mixer controller 144 which controls the frequency shifting of the input mixer means and the output mixer means and a phase/band width controller 146 to control the band width and the phase characteristic of the controllable bandpass filter means.