The disclosure provides a manufacturing method for a circuit board having a via and including a substrate, a ground conductor, a floated conductor and a signal conductor. The substrate includes a second sheet layer, a second ground layer, a core layer, a first ground layer and a first sheet layer that are stacked in sequence from bottom to top. The ground conductor penetrates through the core layer and is electrically coupled to the first ground layer and the second ground layer. The floated conductor penetrates through the core layer and is electrically insulated from the first ground layer, the second ground layer and the ground conductor. The signal conductor penetrates through the substrate, being located between the ground conductor and the floated conductor, and insulated from the first ground layer, the second ground layer, the ground conductor and the floated conductor.