Control method, computer program product, control device for engine and engine

One example method for an engine having an automatic stopping function in which the engine is automatically stopped when a predetermined engine stopping condition is satisfied, and then the engine is automatically restarted when a predetermined engine restarting condition is satisfied, includes the following: a first step for driving a motor so as to increase an engine rotating speed of the engine up to a predetermined rotating speed and maintain the engine rotating speed, in a case in which a predetermined first condition is satisfied when the engine rotating speed is below the predetermined rotating speed during automatic engine stopping; and a second step for restarting a fuel supply into the engine in a case in which a predetermined second condition is satisfied after the first step is executed.