A magnetoencephalography meter for measuring neuromagnetism in the head of a subject is provided with a plurality of optically pumped magnetometers arranged so as to form a helmet shape covering the subject's head, the optically pumped magnetometers comprising: vapour cells which are filled with alkali metal atoms and are arranged so as to be almost parallel with the surface of the subject's head; laser light emission means which emit laser light in the direction going toward the subject's head, which is the direction almost perpendicular to the surface of the subject's head, and cause laser light to enter into the vapour cells; reflection means which reflect the laser light having passed through the vapour cells, in the direction going away from the subject's head, which is the direction almost perpendicular to the surface of the subject's head; and polarisation change detection means which receive the laser light reflected by the reflection means and detect any change in the polarisation of the laser light.
MAGNETOENCEPHALOGRAPHY METER AND NEUROMAGNETISM MEASURING METHOD