The instrument to be described measures magnetic field strengths as determined from the Hall effect in germanium. The essential parts of this instrument include a small germanium probe, and a panel type microammeter calibrated directly in gauss. Its accuracy is ±2 percent at fields between 100 and 8000 gauss. At higher fields the readings are too low, the error amounting to 9 percent at 20,000 gauss. The chief advantages of this instrument are: (a) small size and portability, (b) continuous reading rather than ballistic as in ordinary field strength meters, and (c) a small non‐magnetic probe with which one can search in very narrow gaps.