A male connector (10) is provided with a housing main body (20) formed with a plurality of cavities (21) penetrating in forward and backward directions, into which terminal fittings are insertable, a surrounding wall portion (36) arranged at a rear part of the housing main body (20) and open backward, and a plurality of seal tower portions (35) arranged inside the surrounding wall portion (36) at the rear part of the housing main body (20) and surrounding the cavities (21). Outer ribs (41) extend between the inner surfaces of the surrounding wall portion (36) and the outer surfaces of the seal tower portions (35). The outer ribs 41 are thick at connected parts with the surrounding wall portion (36) while being thin at connected parts with the seal tower portions (35).