An investigation is made of the dependence of concentration and mobility of electrons on the dopant concentration and some data are given concerning the temperature dependence of the Hall coefficient in heavily doped n‐InSb crystals in the temperature range 300 to 750 °K. It is found that the relative increase of the Hall coefficient with temperature depends on the concentration and nature of the doping impurity. Two possible variants of qualitative explanation of the obtained experimental results are offered: 1. Formation of complexes in heavily doped InSb crystals. 2. The influence of the second conductivity band on the properties of heavily doped InSb crystals.