A cosmetic application device includes the application stick and the application portion having the brush fixedly mounted at the end of the application stick by the cylindrical capsule, wherein corner portions of the inner surface and the outer surface of the capsule are chamfered so as not to leave sharp edges. Also, the thin and soft protection tube is disposed between the brush and the capsule with the end of the tube extending slightly beyond the end of the capsule, thereby preventing the brush from being bent at an acute angle to avoid broken hair of the brush.