In this lubricant distribution acquisition device (1), neutron beams that have been transmitted through a bearing (X) are converted into electromagnetic waves, and, by using the received electromagnetic waves to form images based on rotation angle signals that are output from an encoder (5) and show a rotation angle of the bearing, lubrication distribution data that shows the distribution of a lubricant inside the bearing is acquired. As a result, it is possible to make the pitch of the rotation angle uniform in each set of imaging data, and to thereby accurately ascertain the behavior of the lubricant inside the bearing.