A process for separating monosilane from a mixture comprising monosilane and chlorosilanes comprising: a) Introducing mixture to a condenser (3) for separating lower-boiling chlorosilanes—containing monosilane from higher-boiling chlorosilanes enriched condensates; b) Collecting said higher-boiling condensates, in a condensate buffer (19) connected to the aforesaid condenser (3) by a condensate feed pipe (8); c) Sending higher-boiling chlorosilanes enriched condensates from the aforesaid condensate buffer (19) into a subcooler (21) which is installed on a reflux feed line (7) connected to the upper portion of a chlorosilane absorber (20); d) Feeding lower-boiling chlorosilanes—containing monosilane to the aforesaid chlorosilane absorber (20) for separating monosilane; e) Extracting monosilane—rich gas from the upper portion of the aforesaid chlorosilane absorber (20).