Provided is a brain function measuring device which detects a brain magnetic field and living organism scattered light with higher sensitivity and more easily than in the prior arts. By affixing a light transmission probe (120a) and a light reception probe (120b) to recessed sections (122a, b) formed in the surface of a cryostat (110) for cooling and holding a SQUID fluxmeter (100) with elastic members (121a, b) that extend and contract in a light detection direction interposed therebetween, the cryostat can approach within a distance of 5 mm or less from the scalp of a subject while the light transmission/reception probes are in contact with the scalp. Moreover, the SQUID fluxmeter and the light transmission/reception probes are disposed so as not to interfere with each other and so that the signal intensities of a brain magnetic field and living organism scattered light become maximum.
BRAIN FUNCTION MEASURING DEVICE