Abstract: A ball joint comprises: a ball stud having a spherical head at an end thereof; a ball seat into which the spherical head is slidably fitted so as to universally support the ball stud; and a housing for accommodating the ball seat. The ball seat and the housing have surfaces opposing each other, and recesses communicated with each other are formed on the surfaces. The recesses are filled with a resin, so that relative movement of the ball seat with respect to the housing is restricted.