PURPOSE: To improve operation efficiency by operating the truck kick-out device installed in an inlet lifter part with the truck tensile engaged device installed in a working conveyor, and making a greening truck so as to be delivered to the conveyor, in case of a device which transfers nursery boxes stacked up in shelf form onto the greening truck.

CONSTITUTION: When an inlet lifter part 32 is brought down to a floor surface, an outlet lifter part 33 goes up to a working conveyor 31, waiting for a greening truck loaded with a nursely box 1. And, the empty greening truck 12 is mounted on the inlet lifter part 32, making it go up to the working conveyor 31, and when this working conveyor 31 is driven, a truck tensile engaged device 42 comes into contact with a receiver member 43, and a gear 46 is rotated in an arrow direction. With this rotation, a kick-out member 44 is rotated in the arrow direction via a gear 48, and the greening truck 12 mounted on the inlet lifter part 32 is extruded to the working conveyor 31, thus it is transferred onto this conveyor. With this constitution, truck transference is automated, thus improvement in operation efficiency is promoted.