There is provide a magnetic field measurement device including: a magnetic sensor array configured by a plurality of magnetic sensor cells, each of which has a magnetic sensor; a magnetic field acquisition section configured to acquire measurement data measured by the magnetic sensor array; a signal space separation section configured to perform signal separation to separate, into internal space data and external space data, a spatial distribution of a magnetic field which is indicated by the measurement data, based on a position and a magnetic sensitivity of each magnetic sensor; and a calculation processing section configured to remove, from the internal space data, at least a part of a variation component common to magnetic field measurement data that indicates the spatial distribution of the magnetic field which is indicated by the measurement data, and the external space data.