Active vibration damping actuator and active damping apparatus using the same

A vibration damping actuator including: a cup-shaped housing; an output member disposed spaced apart from an opening end of the housing; a guide rod disposed on the output member and positioned inserted into a guide hole; a coil member provided to one of the housing and the output member; an armature disposed on an other of the housing and the output member, the armature being adapted to exert actuating force on the output member; an annular fixing member arranged about the output member; a support rubber plate disposed between the annular fixing member and the output member; and a positioning projection formed at an inside peripheral edge of the fixing member by projecting the inside peripheral edge of the fixing member in cylindrical configuration in an axial direction towards an inside of the housing. The positioning projection is disposed at a location situated inward by a predetermined distance from the opening of the housing for positioning the fixing member relative to the housing.