There is provided a frame processing device includes a plurality of output ports; a table in which a destination address is stored in association with an output port; a buffer configured to store a learned frame, an un-learned frame, and a copy frame generated by copying the un-learned frame; a transfer unit configured to read a second frame from the buffer in an order in which the second frame is stored and transfer the second frame to a predetermined output port; a storage configured to store the destination address of the learned frame; and a controller configured to discard the second frame to be transferred by the transfer unit, when the second frame is the un-learned frame and the destination address of the second frame is stored in the storage, wherein the second frame transferred to the plurality of output ports is output as the first frame.