Supercharge pressure control apparatus and method

A supercharge pressure control apparatus of the invention is characterized by comprising an electric motor (11b) for rotating a turbine/compressor (11a) of a turbocharger (11) so as to provide supercharge pressure, supercharge pressure changing means other than the electric motor-equipped compressor, and supercharge pressure changing means for performing a supercharge pressure control by the supercharge pressure changing means with priority over the supercharge pressure control by the first supercharge pressure changing means. Therefore, in the turbocharger (11) having the electric motor (11b) and the supercharge pressure changing means other than the electric motor (11b), the supercharge pressure can be controlled without interference between the control by the electric motor (11b) and the control by the other supercharge pressure changing means, thus contributing to improvements in output characteristic and fuel economy.