Abstract: A multilayer wiring board exhibiting excellent moldability and having a capacitor where variation of capacitance is suppressed, its producing method, a semiconductor device mounting a semiconductor chip on the multilayer wiring board, and a radio electronic device mounting the semiconductor device.

Abstract: A method of purifying a polypeptide having a physiological activity such as one having interferon activities from a culture mixture of a microorganism obtained by a recombinant DNA technique and capable of producing the polypeptide is disclosed. The method comprises subjecting the cultured cells to extraction and purification in the presence of a salt of zinc or copper and polyethyleneimine thereby inhibiting decomposition and denaturation of the polypeptide. The extracted polypeptide can be further purified by column chromatographies using a column containing an anion exchange resin, column containing a cation exchange resin and column containing a gel filtration resin.