A system for supplying respiration gas, comprising: a respiration gas source; a pressure control module for actuating the respiration gas source to specify a respiration gas pressure at an expiratory pressure (PEEP, EPAP) and an inspiratory pressure (IPAP) that is higher than the expiratory pressure (PEEP, EPAP); a flow control module for actuating the respiration gas source to specify a respiration gas flow; a pressure sensor apparatus for providing a pressure signal; a flow sensor apparatus for providing a flow signal; a user interface for specifying parameters of the respiration gas supply or for exchanging data; a memory for storing the specified parameters; a control unit which is configured to activate the pressure control module or flow control module based on a specification input by a user via the user interface or to automatically select said pressure control module or flow control module based on information stored in the memory and to actuate said pressure control module or flow control module with specification of the parameters, wherein the control unit is further configured to recognize interrupted breathing from the pressure signal and/or flow signal, wherein the respiration gas source is actuated during the day for flow control and specifying the respiration gas flow and during the night for pressure control and specifying at least one respiration gas pressure level that is modulated depending on the pressure signal and/or flow signal, wherein the respiration gas pressure level - if interrupted breathing was recognized - is modulated such that the pressure specifications specify a higher difference between EPAP and IPAP, wherein the control unit is further configured to attempt to generate a set respiration gas flow when the flow control module is activated, wherein a respiration gas pressure required for this is determined, wherein - if the respiration gas pressure required for this comes up against a specified threshold for a determined period of time - a switch takes place to the pressure control module and a specified maximum permissible respiration gas pressure is maintained even if the generated respiration gas flow is below the set respiration gas flow, and - if the set respiration gas flow is again reached or exceeded for a determined period of time - a switch takes place back to the flow control module; wherein the system further comprises a respiration gas tube and a patient interface and, additionally, at least one humidifier and/or an oxygen source and/or a nebulizer and/or a heater, characterized in that the EPAP level comprises at least two pressure levels and rises from an initially low EPAP up to the end of expiration. a respiration gas source; a pressure control module for actuating the respiration gas source to specify a respiration gas pressure at an expiratory pressure (PEEP, EPAP) and an inspiratory pressure (IPAP) that is higher than the expiratory pressure (PEEP, EPAP); a flow control module for actuating the respiration gas source to specify a respiration gas flow; a pressure sensor apparatus for providing a pressure signal; a flow sensor apparatus for providing a flow signal; a user interface for specifying parameters of the respiration gas supply or for exchanging data; a memory for storing the specified parameters; a control unit which is configured to activate the pressure control module or flow control module based on a specification input by a user via the user interface or to automatically select said pressure control module or flow control module based on information stored in the memory and to actuate said pressure control module or flow control module with specification of the parameters, wherein the control unit is further configured to recognize interrupted breathing from the pressure signal and/or flow signal, wherein the respiration gas source is actuated during the day for flow control and specifying the respiration gas flow and during the night for pressure control and specifying at least one respiration gas pressure level that is modulated depending on the pressure signal and/or flow signal, wherein the respiration gas pressure level - if interrupted breathing was recognized - is modulated such that the pressure specifications specify a higher difference between EPAP and IPAP, wherein the control unit is further configured to attempt to generate a set respiration gas flow when the flow control module is activated, wherein a respiration gas pressure required for this is determined, wherein - if the respiration gas pressure required for this comes up against a specified threshold for a determined period of time - a switch takes place to the pressure control module and a specified maximum permissible respiration gas pressure is maintained even if the generated respiration gas flow is below the set respiration gas flow, and - if the set respiration gas flow is again reached or exceeded for a determined period of time - a switch takes place back to the flow control module; wherein the system further comprises a respiration gas tube and a patient interface and, additionally, at least one humidifier and/or an oxygen source and/or a nebulizer and/or a heater, characterized in that the EPAP level comprises at least two pressure levels and rises from an initially low EPAP up to the end of expiration.