Cr-adsorbed GaAs ( 0 0 1 ) ‐ c ( 4 × 4 ) α surfaces were investigated in view of a preparatory stage before studying the growth of zincblende CrAs. Cr was adsorbed on a GaAs ( 001 ) ‐ c ( 4 × 4 ) α surface at 200 °C followed by annealing for 2 min. Cr adsorbed surface was investigated with scanning tunneling microscopy at 80 K. Single Cr atom was identified after the classification of Cr dots grown on the surface. The results have suggested that a Cr atom adsorbs on a site between three Ga–As dimers. After further adsorption of Cr, the surface is covered by dots which are higher than a step height of the substrate.