An alignment apparatus for dynamically operating lanes in a high speed Ethernet device having multiple lanes, includes: a PCS (Physical Coding Sublayer) upper layer managing lane information regarding all of the lanes and operational lanes; a PCS transmission unit receiving the lane information from the PCS upper layer and inserting an alignment marker into the operational lanes; a PMA (Physical Medium Attachment) layer receiving the alignment marker from the PCS transmission unit and transmitting the same, and receiving alignment marker from another alignment apparatus; and a PCS reception unit receiving the lane information from the PCS upper layer, receiving the alignment marker from the PMA layer, and performing alignment on the operational lanes.