To provide a variable speed conveyor device for safely transferring materials to be carried, while restricting the generation of noises, on an endless carrying route having a plurality of straight parts and curved parts.

This variable speed conveyor device is formed of an endless transporting stand formed of straight parts and curved parts and formed with a recessed groove, which is provided with air injection openings, over the whole of the circumference and provided with an air chamber under the recessed groove, pallets arranged on the top surface of the transporting stand over the whole of the circumference and connected to each other to be overlapped with each other freely to slide, and a plurality of speed variable devices provided in the transporting stand to drive the pallets.