Abstract: A miniature Kerr effect probe is described which may be used to examine surfaces of magnetic material during electroplating or vacuum deposition, without requiring a specially shaped bath or chamber.The probe consists of a U-shaped core with adjacent pole tips of soft magnetic material wound with a coil to provide a magnetic field across the ends of the arms of the core which constitute probe tips. In use, these probe tips are placed adjacent to a surface being examined. Optic fibers are used to direct light to and from the surface.The polarizer and analyzer required for Kerr work may be at the probe tips or remote from the probe tips due to the availability of optic fibers which will transmit polarized light without distortion. The light beam at the probe tips may be collimated or focussed by the optic fiber.