A manufacturing method of a package structure of an electronic device, including the following steps, is provided. A first seed layer is formed on a carrier plate. A first metal layer is formed on the first seed layer. A first insulating layer is formed on the first metal layer, wherein the first insulating layer exposes a portion of the first metal layer. A first plasma treatment is performed on the first insulating layer and the exposed portion of the first metal layer. After performing the first plasma treatment, the carrier plate formed with the first seed layer, the first metal layer, and the first insulating layer is placed in a microenvironment controlling box. After taking the carrier plate out of the microenvironment controlling box, a second seed layer is formed on the first insulating layer and the exposed portion of the first metal layer.