To provide a pallet replacing device capable of enhancing the efficiency of the storing operation by automating the pallet replacing operation for replacing a pallet storing objects processed with an empty pallet.

The pallet replacing device 1 is to replace the pallet 2 storing the objects processed with any pallet empty 2, each pallet 2 capable of storing a specified number of objects processed, and is equipped with a pallet dolly 3 to admit placing of the pallet 2 and a transporting mechanism to transport the pallet dolly 3 to the replacing operation position (3) and transport the pallet dolly 3 whereon the empty pallet 2 is placed to the pallet storing operation position (1).