A method for manufacturing passive devices and semiconductor packages using a thin metal piece is provided. According to the method, an adhesive layer is formed on a dummy substrate; a thin metal piece is bonded on the adhesive layer; a masking material is attached to the thin metal piece, a region where vias are to be formed is patterned, the thin metal piece is etched at a predetermined depth; the masking material is removed, the etched portion is filled with polymer to form a flat polymer layer, a masking material is attached on the polymer layer, a region that is to be attached to an IPD or an IC chip is patterned, a metal pad is formed, and the formed devices are attached to a lower substrate using the metal pad; the adhesive layer and the dummy substrate are removed, a masking material is attached on a surface exposed, a region where passive devices are to be formed is patterned, and the thin metal piece is etched at a predetermined depth; and solder bumps for surface mounting are formed.