In a magnetic field measurement apparatus and a magnetic field measurement method provided herein, a magnetic field from an object is measured by a magnetic sensor group including a plurality of magnetic sensors. Then, an estimated value of a common noise component included in observed quantities of the magnetic sensors of all the channels of the magnetic sensor group is obtained as an external magnetic noise component. Finally the magnetic signal from the object is calculated by subtracting the estimated value from the observed quantity of each of the magnetic sensors.