The invention discloses a dishwasher. The dishwasher includes a cabinet which forms an exterior appearance thereof, the cabinet having a door on one side thereof, which can be opened and closed, a tub provided in the cabinet to form a cleaning object housing space, a rack provided to the tub for securing cleaning objects thereto, a spray module rotatably provided for spraying cleaning water toward the cleaning objects, and a supply flow passage for supplying the cleaning water to the spray module, thereby permitting to provide a housing space larger than an existing dishwasher, and a spray module which can wash cleaning objects with an excellent effect.