The relative electrical resistance and the thermal e.m.f. of antimony single crystals are measured under hydrostatic pressure up to 8 GPa at room temperature. The first order polymorphic transition of antimony from the rhombohedral to the simple cubic structure supposed before is nonexistent at these conditions. The polymorphic transition SbI SbII occurs at pressures 5.7 to 7.8 GPa under shear stress conditions, the single crystal being undestroyed. The high pressure SbII and the rhombohedral SbI phases exibit similar electronic properties in this pressure range. Antimony doesn't posses the metallic properties up to 7.8 GPa when the metallic SbIII phase forms. [Russian Text Ignored].