Device for compressing and drying gas includes a multistage compressor with a low pressure stage, a high pressure stage, and a pressure pipe; and an adsorption dryer with a drying zone and a regeneration zone. An intercooler is located between the low pressure stage and high pressure stage, and the device includes a heat exchanger with a main compartment with an inlet part and an outlet part for a first primary fluid. The ends of the tubes of the heat exchanger are connected to a separate inlet compartment and outlet compartment for each series of tubes. A first series of tubes forms a cooling circuit of the intercooler in order to heat up gas from the high pressure stage for the regeneration of the adsorption dryer.