A vapor chamber with a support structure and its manufacturing method are provided. The vapor chamber with the support structure includes a first plate, a second plate spaced apart from the first plate, and multiple support elements fixed between the first and second plates. On an outer surface of any of the first plate or the second plate, laser welding is performed on positions corresponding to the support elements so as to join the support elements to the first and second plates and to form weld ports on the outer surface of any of the plates. The invention solves the problem of fixing the support structure inside the thin vapor chamber, and therefore mass production can be realized.