Disclosed herein is a dishwasher including a spray unit fixed to one sidewall of a wash tub and a reflecting plate assembly to reflect wash water sprayed from the spray unit onto dishes and to linearly reciprocate in a spray direction of the wash water sprayed from the spray unit. The dishwasher further includes a drive unit to drive the reflecting plate assembly, and a cam unit to transmit driving force of the drive unit to the reflecting plate assembly. The drive unit includes a motor to generate rotational force, and a belt forming a closed loop and caused to make cyclic movement by the motor. The cam unit is engaged with the belt to transmit power of the belt to the reflecting plate assembly. The cam is alternately engaged with first and second portions of the belt to cause the reflecting plate assembly to reciprocate.