PROBLEM TO BE SOLVED: To provide: a radical functional solution having radicals in plasma gas which are dissolved into a solvent, has a lifetime of activity longer than that of radicals in the atmosphere and are controlled so as to lose the activity thereof in a desired period of time a method for manufacturing the radical functional solution and a method for using the radical functional solution.SOLUTION: The radical functional solution is a solution obtained by dissolving radicals resulting from plasma gas in a solvent so as to lose a function as a functional solution in a predetermined time. There are provided a method for manufacturing the radical functional solution and a method for using the radical functional solution.