A biomagnetic field measurement apparatus capable of easily bringing the sensor planes close to the head surface of the subject and capable of detecting cerebral magnetic fields of the left brain and the right brain simultaneously with a higher sensitivity is provided by disposing two independent cryostats holding SQUID fluxmeters in the mirror image relation to each other. The two cryostats move vertically and horizontally and rotate while interlocking with each other and maintaining the mirror image relation to each other. A gantry holding the cryostats has a function of suppressing vibration of the cryostats and has a gate shape.