To suggest a method for inspecting an engine for simplifying a wire connection operation which becomes necessary when an engine body and an electric product attached to the engine body are inspected.

An engine is equipped with sensors, actuators and a controller which is connected to them via harnesses, respectively to control the engine. All of a plurality of harnesses are connected to the controller via a relay connector board attached to the engine. A method for inspecting the engine includes: a connection step of connecting an inspection device to the relay connector board instead of the controller; an engine actuation step of starting the inspection method following the connection step; and an inspection execution step of performing actuation inspections of the sensors and the actuators following the engine actuation step.