A biomagnetism measuring device includes a magnetic sensor and a support unit. The magnetic sensor includes a tunnel magneto-resistive element including a fixed magnetic layer, a free magnetic layer and an insulating layer. The insulating layer is disposed between the fixed magnetic layer and the free magnetic layer, and has resistance being changed by a tunnel effect depending on an angle difference between a direction of magnetization of the fixed magnetic layer and a direction of magnetization of the free magnetic layer. The support unit supports the magnetic sensor in such a way that the tunnel magneto-resistive element faces a living body. The magnetic sensor outputs an output signal in accordance with a resistance value of the insulating layer, the resistance value being changed by magnetism emitted from the living body.
