SURFACE TREATMENT AGENT

To provide a surface treatment agent enabling formation of a film which is excellent in hydrophilic property and corrosion resistance, and is suppressed in odor.SOLUTION: A surface treatment agent is provided, containing one or more kinds selected from a water-soluble inorganic oxide and a salt thereof (A), one or more kinds selected from a hydrolysate and a condensate of organoalkoxysilane (B), a water-soluble resin (C), an ether compound (D), and water and/or a water-miscible solvent, wherein when the total mass of the one or more kinds selected from the water-soluble inorganic oxide and the salt thereof (A), the total mass of the one or more kinds selected from the hydrolysate and the condensate of the organoalkoxysilane (B), the mass of the water-soluble resin (C) and the mass of the ether compound (D) are represented by MA, MB, MC and MD, respectively, the surface treatment agent satisfies equation, (MA+MB)/(MA+MB+MC+MD) is 0.01 to 0.7.SELECTED DRAWING: None 【課題】親水性及び耐食性に優れ、且つ、臭気の抑制された皮膜を形成可能な表面処理剤を提供する。【解決手段】水溶性無機酸化物及びその塩（Ａ）から選ばれる１種以上と、オルガノアルコキシシラン（Ｂ）の加水分解物及び縮合物から選ばれる１種以上と、水溶性樹脂（Ｃ）と、エーテル化合物（Ｄ）と、水及び／又は水混和性溶媒とを含有し、水溶性無機酸化物及びその塩（Ａ）から選ばれる１種以上の合計質量、オルガノアルコキシシラン（Ｂ）の加水分解物及び縮合物から選ばれる１種以上の合計質量、水溶性樹脂（Ｃ）の質量、及びエーテル化合物（Ｄ）の質量をそれぞれＭA、ＭB、ＭC及びＭDで表すと、（ＭA＋ＭB）／（ＭA＋ＭB＋ＭC＋ＭD）＝０．０１～０．７である、表面処理剤。【選択図】なし