A charging device for an internal combustion engine, having an exhaust turbocharger and a recuperation-charger having a compressor-turbine and an electromechanical motor-generator coupled thereto. The high-pressure side of the compressor-turbine is connectable, by a valve arrangement, to the outside air supply line before the exhaust turbocharger on one side and on the other side, to the charge air supply line after the exhaust turbocharger. Outside air can be suctioned or charge air blasted via the low-pressure side of the compressor-turbine. The recuperation-charger is switched, by the valve arrangement and the motor-generator, between a standard mode, an amplifier mode and a recuperation mode, wherein the recuperation-charger operates on one side in the amplifier mode, driven by the motor-generator, as a compressor for pressure increase in the outside air supply line or, on another side, driven by the charge air flow, acts as a turbine for energy recovery by the motor-generator.