We have constructed a simple laser‐pumped device for a visible and real‐time display of an inhomogeneous magnetic field in three dimensions. Photographic records of such displays in the form of constant‐field contours spaced 5 mG apart are presented. Our device is capable of high spatial resolution, and we have observed contour lines as sharp as 0.02 cm full width. Such real‐time high‐resolution contours cannot be obtained by conventional point‐by‐point mapping. Our device can also be used as an unconventional rf frequency spectrum analyzer.