In order to provide a
new production method of a suspension board with circuit capable of preventing deterioration of the outward appearance and defects in products caused by a
metal supporting layer, and further capable of forming an
electroless nickel plating layer having an even thickness in a reliable manner, an insulating base layer is first formed on a supporting board, and a
chromium thin film and a
copper thin film are formed next sequentially on the surface of the supporting board exposed from the insulating base layer and on the entire surface of the insulating base layer. Subsequently, a plating
resist is formed in a reversal pattern with respect to the wired circuit pattern on the surface of the
copper thin film, and a conductor layer is formed on the surface of the
copper thin film exposed from the plating
resist by electrolytic plating. The plating
resist is removed after an
electroless nickel plating layer is formed on the conductor layer. Subsequently, the
copper thin film and the
chromium thin film are removed sequentially, and an insulating cover layer is formed next.