The invention provides a manufacturing method for a semiconductor device. The manufacturing method of the invention comprises the following steps: firstly, a substrate is provided; secondly, a metal layer and a first dielectric layer are sequentially formed on the substrate through a deposition process; thirdly, the first dielectric layer and the metal layer are etched, and metal wires and first dielectric layer patterns on the metal wires are formed, and a part of the substrate is exposed; fourthly, an obstruction material layer is formed through a deposition process on the substrate and the first dielectric layer pattern; fifthly, the obstruction material layer is etched, and at least one obstruction body is formed between the adjacent metal wires; sixthly, a second dielectric layer is formed on the substrate, the first dielectric layer patterns, and the obstruction body, and gaps are formed between the metal wires and the obstruction body and / or in the second dielectric layer between the adjacent obstruction bodies. Through the adoption of the above method, the gaps can be formed in the second dielectric layer between the metal wires, and the dielectric constant of the second dielectric layer can be effectively reduced. A parasitic capacitance between the metal wires can be reduced and the condition of a RC delay of the interconnected metal wires is improved.