Upon returningfrom the front, Berezin was appointed deputy head of CEKA, responsible for the activity of CEKA. Here accomplished important things regarding the organization of training courses for CEKA personnel that later was transformed into the Academy of Federal Security Service (FSB). In August 1921 he was appointed by Dzerzhinsky responsible to carry out special missions under the President of CEKA. In the same year, Berezin received additional mandate from Felix Dzerzhinsky, already also the People's Commissar of Railways, he is promoted to the position of president of the Industrial Association "Trestputi" that was formed of a conglomerate of mechanical enterprises, foundry and woodworking factories. He was awarded collegial diploma GPU and badge "Honorary Worker of CEKA-GPU". In 1940- 1941, Berezin led the trust "Electrostroi" in Moscow. With the start of the Second World War he was appointed head of military equipment factory No. 287 of the Commissariat of Aviation Industry of the USSR in Vladimir city. In 1942 he became head for reconstruction ofelectrothermal plant of Stalinogorskin Moscow re- gion and member ofthe Government commission for restoration of energetic objects. Since 1943, Berezin has been managing the Mosenergomontazh trust. In 1951-1952, director of the Perlovsky experimental plant of the USSR Ministry of Power Plants.