Wired circuit board and producing method thereof

A method for producing a wired circuit board, the method comprising:

• preparing a metal supporting board;
• forming an insulating layer on the metal supporting board;
• forming an underlying layer on the insulating layer;
• forming a conductive layer on the underlying layer;
• etching the underlying layer exposed from the conductive layer to form a conductive pattern;
• further etching the underlying layer to form a corroded portion in the underlying layer corroded from a side end portion of the conductive layer toward an inner portion thereof;
• and
• sputtering from above the conductive pattern in a thickness direction thereof so as to form a semiconductive layer on a surface of the insulating layer and on a surface of the conductive pattern such that the semiconductive layer comes in contact with the metal supporting board and a cut is formed in the corroded portion to interrupt conduction between the semiconductive layer formed on the surface of the insulating layer and the semiconductive layer formed on a surface of the conductive layer.