The dishwasher includes a cabinet provided with a washing space inside thereof, and a nozzle unit for spraying washing water into the washing space. The nozzle unit includes a first unit body and a second unit body. Any one of the first and second unit bodies includes a first coupling rib formed along at least a portion of the periphery and a second coupling rib spaced apart from the first coupling rib by a predetermined distance. The other of the first and second unit bodies includes a third coupling rib inserted between the first and second coupling ribs and a second coupling rib located inside the third coupling rib, and stepped ribs configured to face each other.