A holding device having a printed circuit board includes a base having a securing recess at a top surface thereof, a securing connector fixed in the securing recess and connected with the printed circuit board, a holding shell rotatably covered to the securing connector, and a flexible antenna of flat plate shape. The antenna has a rectangular radiating body, and a strip-shaped connecting portion extended outwards from a side of the radiating body. A free end of the connecting portion is held by the holding shell and rotated to connect with the securing connector electrically and detachably. An exposed portion of the connecting portion is bent so that the radiating body is attached to the top surface of the base.