A control apparatus for an internal combustion engine, the internal combustion engine including: an intake passage through which intake air taken into a cylinder flows; an exhaust passage through which exhaust gas from the cylinder flows; intake air flow rate regulation means provided in the intake passage and configured to regulate an intake air flow rate of air that is taken into the cylinder; a turbocharger including a turbine arranged in the exhaust passage, a turbo compressor arranged in the intake passage, a connection shaft that connects the turbine and the turbo compressor, and an oil seal portion that is provided on the connection shaft at a location on a rear surface side of an impeller (22a1) of the turbo compressor; an electric supercharger including an electric compressor arranged in the intake passage on an upstream side of the turbo compressor, and a motor generator that is a drive source of the electric compressor and configured to function as a generator when regeneration is performed; an intake bypass passage connecting the intake passage on an upstream side of the electric compressor, with the intake passage which is at a downstream side of the electric compressor and at an upstream side of the turbo compressor; and an intake bypass valve configured to open and close the intake bypass passage, the control apparatus characterized by comprising a regenerative processing section that is configured to execute regenerative processing with the electric supercharger, by controlling an intake air flow rate, an opening degree of the intake bypass valve and a power generation load on the motor generator, and wherein the regenerative processing section is configured, at a time of execution of the regenerative processing, to set at least one of the opening degree of the intake bypass valve and the power generation load on the motor generator, based on a request intake air flow rate (GaR) of the internal combustion engine, a rotational speed (Nt) of the turbocharger, and a first specific pressure value (P3L) which is a pressure value of a first intake pressure that is an intake pressure at an outlet of the turbo compressor and which satisfies a condition where oil leakage to a side of the turbo compressor from the oil seal portion does not occur. an intake passage through which intake air taken into a cylinder flows; an exhaust passage through which exhaust gas from the cylinder flows; intake air flow rate regulation means provided in the intake passage and configured to regulate an intake air flow rate of air that is taken into the cylinder; a turbocharger including a turbine arranged in the exhaust passage, a turbo compressor arranged in the intake passage, a connection shaft that connects the turbine and the turbo compressor, and an oil seal portion that is provided on the connection shaft at a location on a rear surface side of an impeller (22a1) of the turbo compressor; an electric supercharger including an electric compressor arranged in the intake passage on an upstream side of the turbo compressor, and a motor generator that is a drive source of the electric compressor and configured to function as a generator when regeneration is performed; an intake bypass passage connecting the intake passage on an upstream side of the electric compressor, with the intake passage which is at a downstream side of the electric compressor and at an upstream side of the turbo compressor; and an intake bypass valve configured to open and close the intake bypass passage, the control apparatus characterized by comprising a regenerative processing section that is configured to execute regenerative processing with the electric supercharger, by controlling an intake air flow rate, an opening degree of the intake bypass valve and a power generation load on the motor generator, and wherein the regenerative processing section is configured, at a time of execution of the regenerative processing, to set at least one of the opening degree of the intake bypass valve and the power generation load on the motor generator, based on a request intake air flow rate (GaR) of the internal combustion engine, a rotational speed (Nt) of the turbocharger, and a first specific pressure value (P3L) which is a pressure value of a first intake pressure that is an intake pressure at an outlet of the turbo compressor and which satisfies a condition where oil leakage to a side of the turbo compressor from the oil seal portion does not occur.