PROBLEM TO BE SOLVED: To favorably maintain an engine driving state by positively avoiding an engine stall caused by dropping of an engine speed, in an engine system equipped with an electronical control throttle device. SOLUTION: In the throttle electronic control method carried out by the electronically controlled throttle device 1A carrying out opening and closing control of the throttle 3 via an actuator 7 by a command of an electronic control unit 10A, the electronic control unit 10A detects a neutral switch output signal, an engine speed sensor signal, and a vehicle speed sensor signal. If a shift position of a transmission is in a gear connected state, a vehicle speed is a predetermined determination traveling speed or more, and an engine seed is lower than a predetermined engine speed having a danger of causing an engine stall, throttle control is carried out to maintain an engine speed of a predetermined target engine speed or more to avoid an engine stall. COPYRIGHT: (C)2008,JPO&INPIT