To provide a unloading device with a movable plate stably movable when moved integrally with a thrust member, the movable plate only being movable without operating friction force between the movable plate and the thrust member when moving the movable plate only, and to provide a truck using the same.

The thrust member 4 is moved outward together with the movable plate when moving the movable plate 2 outward and the thrust member 4 is stopped at this position when moving the movable plate 2 homeward. Thus, loads are pushed out to the side of an unload opening portion 15. An engagement member 75 for engaging with the movable plate 2 when moving the movable plate 2 outward is provided on the thrust member 4. The engagement 75 disengages therefrom when moving the movable plate 2 homeward.