A laundry treating apparatus includes: a cabinet, a water tank provided inside the cabinet, and a detergent box provided in communication with the water tank to supply detergent to an inside of the water tank. The detergent box includes: a housing in communication with the water tank; a drawer received inside the housing; and a ventilation portion formed through the housing so as to allow an inside of the tank to communicate with an outside of the housing, and the ventilation portion includes a through hole formed through a side surface of the housing, and a protruding groove portion recessed from an inner surface of the housing and protruding from an outer surface thereof and to be open at upper and inner sides thereof, respectively, at a lower side of the through hole. The leakage of wash water through the ventilation portion of the housing may be suppressed.