In a magnet stack, an eddy current channel is cut off by an insulating layer in an insulating region of facing surface regions of the pair of magnets. Meanwhile, in a conducting region of the facing surface region of the pair of magnets, electrons can move between the pair of magnets via a conductor, and heat can be exchanged between the pair of magnets by the movement of electrons. Therefore, in the magnet stack, by cutting off the eddy current channel in the insulating region of the facing surface region of the pair of magnets, the degradation in magnet performance is suppressed and the cooling efficiency of the magnet is enhanced in the conducting region.