To provide engine control devices of a vehicle loaded with various kinds of PTO devices which are manufactured by a uniform manufacturing step without individually remodeling each of them, and also to provide the engine control device applicable to the PTO mode at a uniform quality and at a low cost.

A sub-memory constituted by an unvolatile memory is provided on the engine control device and a parameter selected on this sub-memory at the PTO mode is set from an external tool temporarily connected through an interface. A program control circuit of the engine control device controls an idling speed of the engine at an acceleration input to be selected and acceleration 0 in reference to the parameter set in this sub-memory when it is operated by the PTO mode.