Processing liquid, substrate cleaning method, and method for producing semiconductor devices

[Problem] To provide: a processing liquid for semiconductor devices which exhibits excellent stability over time with respect to residue removal performance, and which exhibits excellent corrosion prevention performance with respect to objects to be processed; a substrate cleaning method which uses said processing liquid; and a method for producing semiconductor devices. [Solution] This processing liquid for semiconductor devices includes: at least one hydroxylamine compound selected from the group consisting of hydroxylamines and hydroxylamine salts; at least one basic compound selected from the group consisting of amine compounds different to the hydroxylamine compound, and quaternary ammonium hydroxide salts; and at least one selected from the group consisting of reductants different to the hydroxylamine compound, and chelating agents. The processing liquid has a pH of 10 or higher.