PROBLEM TO BE SOLVED: To provide a charged particle generation device having a variable region from which charged particles blow out together with air, capable of suppressing reduction in air volume, and capable of preventing invasion of dust through an outlet: and to provide a humidifier.SOLUTION: An ion generating device generates positive/negative ions and blows out the ions through an outlet 80 together with sucked air. One edge part of an outlet lower wall 81 forms part of an edge of the outlet 80, and one edge part of an outlet upper wall 82 facing the outlet lower wall 81 forms another part of the edge of the outlet 80. The outlet upper wall 82 is supported by an axis 86 mounted on a back edge part 81b of the outlet lower wall 81 as a support part so as to come in contact with or separate from the outlet lower wall 81.