Controller of internal combustion engine with supercharger

A controller of an engine with a supercharger includes, for each of cylinders, fuel supply system and an ignition plug. The controller includes an electronic control unit that is configured to: (i) set a basic ignition timing depending on an operation state of the engine, (ii) detect, for each cycle, an abnormal combustion generation cylinder in which an abnormal combustion is generated in a supercharged region, (iii) execute a fuel cut to stop a fuel supply by the fuel supply system for the abnormal combustion generation cylinder, (iv) change an ignition timing of the abnormal combustion generation cylinder to expand a crank angle width between a compression top dead center and the basic ignition timing for several cycles after start of the fuel cut, and (v) execute an ignition cut that prohibits a spark from being generated by the ignition plug, further after elapse of the several cycles is executed.