To prevent descending of a cargo without reducing workability of cargo work.

A vehicle speed value SA and a tilt angle value TA of a fork lift loaded with the cargo are detected. Further, when the tilt angle value TA of the fork lift is less than the predetermined tilt angle value and it travels at a forward inclined attitude, it is limited such that acceleration does not become a constant value. By limitation of the acceleration, the fork lift is slowly accelerated and descending of the cargo loaded on a cargo work device is prevented.