A dishwasher that includes: a washing tub that includes an interior space to accommodate objects; a main arm that is configured to rotate in the interior space and spray water to the objects; an auxiliary arm that is configured to rotate in the interior space and spray water to the objects; a stationary gear unit that is configured to rotate with the main arm, and that includes a plurality of gear teeth; an eccentric gear unit that is configured to rotate based on rotation of the main arm, the eccentric gear unit being in engagement with one or more teeth of the plurality of gear teeth; and a link member that is configured to (i) generate elastic force based on rotation of the eccentric gear unit and (ii) rotate the auxiliary arm based on elastic force is disclosed.