A fast (NTSC TV‐rate), low cost, simple histogram equalization processor is described. In this apparatus, the histogram equalization processing is carried out by the table look‐up method at TV‐rate. The characteristics of the processor, and its applications to the real time and on‐line processing of weak contrast images from the Ultra‐High Voltage Electron Microscope (Osaka University) are described. With this apparatus, equilevel processing, level compression, and level slicing may also be easily carried out.