The experience of modernization of the production of sulfur bythe Claus at JSC «Achinsk Oil Refinery of E. O. C .». The measures for replacement of the contact device sulfur trap, the enrichment of air with oxygen in the thermal stage of the process. Activities undertaken on modernization of production of sulfurallowed to increase output (granulated sulfur), to reduce the load on the main and auxiliary equipment installation, ensure smooth operation of the installation.