PURPOSE: To prevent the disorder of control by performing control without using a detection signal at the time of external electromagnetic waves over the specified value acting upon a detecting part in the case of controlling the engine operating state most appropriately by a control part on the basis of the engine operating state detected by the detecting part.

CONSTITUTION: The microcomputer 2a of a control part 2 obtains air flow, rotating speed, and the like on the basis of the data inputted from the air flow detector 1a of a detecting part 1 through an A/D converter 2c, the data inputted from the rotating speed detector 1b of the detecting part 1 through an A/D converter 2d, the reference control data from a storage circuit 2b, and the like. The microcomputer 2a then controls a fuel injection valve control circuit 3a, an ignition timing control circuit 3b, and the like in an operating part 3. In this case, when strong faulty electromagnetic waves from outside act upon the air flow detector 1a, for instance, the air flow detector 1a becomes abnormal, and its detected data results in error. In order to cope with this, the abnormal state is judged by the microcomputer 2a, and an engine is controlled without using wrong detected data.