One aspect of the present invention resides in a manufacturing method for a semiconductor package, including a covering step of forming a covering insulating layer that covers the surface of a semiconductor element, a film-forming step of forming a resin film on the surface of the covering insulating layer, a circuit pattern-forming step of forming a circuit pattern portion including recesses reaching the surfaces of electrodes of the semiconductor element and a circuit groove having a desired shape and a desired depth, a catalyst-depositing step of depositing a plating catalyst or a precursor thereof on the surface of the circuit pattern portion, a film-separating step of separating the resin film from the covering insulating layer, and a plating processing step of forming a circuit electrically connected to the electrodes, by applying electroless plating to the covering insulating layer, from which the resin film is separated.