A dishwasher is disclosed. The dishwasher includes: a tub that defines a washing compartment; a rack disposed in the washing compartment; a spray arm disposed below the rack and configured to be rotatable, the spray arm including a nozzle configured to spray wash water toward the rack; a connector disposed at the spray arm and having one open surface; a cap configured to cover the one open surface of the connector and coupled to the connector; a magnet disposed in a space defined by the connector and the cap; a gasket disposed between the connector and the cap; and a sensor configured to detect a magnetic force of the magnet.