Etchant, method for roughening copper surface and method for producing printed wiring board

A method for producing a printed wiring board, using an inner layer material having an insulating layer on which a copper foil layer is laminated, the method comprising

• roughening a surface of the copper foil layer of the inner layer material by an etchant;
• subjecting the roughened copper foil layer to patterning to form a copper conductive pattern layer;
• and then laminating an insulating outer layer material on a surface of the copper conductive pattern layer;
• said etchant including a main component containing at
• least one first compound selected from the group consisting of oxo acids represented by one of the following formulae:
• XOm(OH)n and HnXOm+n
• wherein X is a central atom, m is an integer of 0 or more and n is an integer of 1 or more and derivatives thereof and at least one second compound selected from the group consisting of peroxides and derivatives thereof;
• and an auxiliary component containing at least one azole and at least one halide.