In a surface potential distribution measurement method and device, a sample having a surface with a surface potential distribution is scanned using a charged particle beam in a two-dimensional manner. A detection signal caused by the two-dimensional scanning is obtained to measure the surface potential distribution. Charged particles, other than charged particles of the charged particle beam incident to the sample surface by the two-dimensional scanning, with which components of an incidence velocity vector of the charged particles in a direction perpendicular to the sample surface are reversed, are detected so that a detection signal indicating an intensity according to the detected charged particles is obtained in correspondence with a position on the sample surface.