To prevent the occurrence of noise and the uneven wear of members so as to prolong the service lives of the members by preventing the dropping of pallets near the entrance of an ore feeding section.

A pallet running device is constituted in such a way that an endless moving route is formed of an ore feeding section-side sprocket 1 and an ore discharging section-side sprocket 2 each of which is rotationally driven around its horizontal shaft axis and a forward path 3S for sintering and a backward path 3R for returning both of which connect the sprockets 1 and 2 to each other and running wheels 9 are respectively fitted to a plurality of pallets 4 which are arranged in a train along the moving route. In addition, rails 11 for forward path and rails 2 for backward path both of which guide and support the wheels 9 from the downside are provided and a floating preventing device 21 having floating control rails 22 which prevent the floating of the running wheels 9 of the pallets 4 installed to the entrance of the ore feeding section-side sprocket 1 of the backward path 3R for returning.