A method for manufacturing a composite of metal and resin, comprising: a shaping step of shaping a substrate composed of stainless steel by mechanical working, a liquid treatment step including chemical etching by immersing the stainless steel substrate that has undergone said shaping step in a sulfuric acid aqueous solution to chemically etch the surface thereof for providing the surface of said shaped substrate with a ultrafine textured face, in which substantially the entire surface is covered with an ultrafine textured face in which amorphous polygons or particulates with a diameter of 20 to 70 nm are stacked on top of one another and the surface has a surface roughness in which the mean width (RSm) of profile elements made up of said ultrafine textured face is 0,5 to 10 μm and the maximum height of roughness (Rz) is 0,2 to 5 μm, an insertion step of inserting said substrate that has undergone the liquid treatment into a metallic mold for injection molding, an injection step of injecting onto the surface of said inserted substrate one type of resin, and an integration step of integrating said substrate with said one type of resin by said injection; said one type of resin being selected from: a first resin composition in which a polyphenylene sulfide resin is the main component and a polyolefin resin is an auxiliary component, a second resin composition in which a polybutylene terephthalate resin is the main component and a polyetylene terephthalate resin and/or a polyolefin resin is an auxiliary component, and, a third resin composition that is a resin composition in which a mixture of different kinds of aromatic polyamide resins is the main component or a resin composition in which an aromatic polyamide resin is the main component and an aliphatic polyamide resin is an auxiliary component. a shaping step of shaping a substrate composed of stainless steel by mechanical working, a liquid treatment step including chemical etching by immersing the stainless steel substrate that has undergone said shaping step in a sulfuric acid aqueous solution to chemically etch the surface thereof for providing the surface of said shaped substrate with a ultrafine textured face, in which substantially the entire surface is covered with an ultrafine textured face in which amorphous polygons or particulates with a diameter of 20 to 70 nm are stacked on top of one another and the surface has a surface roughness in which the mean width (RSm) of profile elements made up of said ultrafine textured face is 0,5 to 10 μm and the maximum height of roughness (Rz) is 0,2 to 5 μm, an insertion step of inserting said substrate that has undergone the liquid treatment into a metallic mold for injection molding, an injection step of injecting onto the surface of said inserted substrate one type of resin, and an integration step of integrating said substrate with said one type of resin by said injection; said one type of resin being selected from: a first resin composition in which a polyphenylene sulfide resin is the main component and a polyolefin resin is an auxiliary component, a second resin composition in which a polybutylene terephthalate resin is the main component and a polyetylene terephthalate resin and/or a polyolefin resin is an auxiliary component, and, a third resin composition that is a resin composition in which a mixture of different kinds of aromatic polyamide resins is the main component or a resin composition in which an aromatic polyamide resin is the main component and an aliphatic polyamide resin is an auxiliary component. a first resin composition in which a polyphenylene sulfide resin is the main component and a polyolefin resin is an auxiliary component, a second resin composition in which a polybutylene terephthalate resin is the main component and a polyetylene terephthalate resin and/or a polyolefin resin is an auxiliary component, and, a third resin composition that is a resin composition in which a mixture of different kinds of aromatic polyamide resins is the main component or a resin composition in which an aromatic polyamide resin is the main component and an aliphatic polyamide resin is an auxiliary component.