Method for producing wiring circuit board and wiring circuit board

A method for producing a wiring circuit board comprising:

• a first metal layer forming step of forming a first metal layer on one surface in a thickness direction of a metal supporting substrate;
• an insulating layer forming step of forming an insulating layer directly on one surface in the thickness direction of the first metal layer, the insulating layer having a second opening portion;
• a removing step of removing a portion of the first metal layer, the portion being exposed at the second opening portion, to form a first opening portion in order to expose the metal supporting substrate at the first opening portion and the second opening portion;
• a second metal layer forming step of forming a second metal layer over on one surface in the thickness direction of the insulating layer and on a portion of the metal supporting substrate exposed at the first opening portion and the second opening portion;
• and
• a conductive layer forming step of forming a conductive layer on one surface in the thickness direction of the second metal layer;
• wherein the second metal layer is a seed layer over which the conductive layer is formed, and
• wherein in the first opening portion and the second opening portion, the second metal layer is disposed between the conductive layer and the metal supporting substrate, and in contact with the conductive layer and the metal supporting substrate.