A manufacturing method of a circuit board is provided. Providing a substrate, where a first laser resistant structure is disposed on a first dielectric layer and at the periphery of a pre-removing area, a second dielectric layer covers the first laser resistant structure, a circuit layer is disposed on the second dielectric layer, a second laser resistant structure is disposed on the second dielectric layer and at the periphery of the pre-removing area, a third dielectric layer covers the circuit layer and the second laser resistant structure. There are gaps between the second laser resistant structure and the circuit layer, and the vertical projection of the gaps on the first dielectric layer overlaps the first laser resistant structure. A laser machining process is performed to etch the third dielectric layer at the periphery of the pre-removing area. The portion of the third dielectric layer within the pre-removing area is removed.