Disclosed is a laundry treating apparatus including a cabinet having an opening defined therein; a tub disposed inside the cabinet; a drum rotatably disposed inside the tub; a detergent storage unit retractable into the cabinet through the opening, wherein detergent is stored in an storage space of the detergent storage unit; a detergent reservoir having a detergent injection hole defined therein communicating with the storage space of the detergent storage unit; and a detergent cap fitted into the detergent injection hole, wherein the detergent cap includes a ventilation path defined therein to communicate an outside of the detergent reservoir with the storage space of the detergent storage unit, wherein the ventilation path has an outer end communicating with the outside of the detergent reservoir, wherein the outer end is open and extends in a lateral direction of the detergent cap.