N.H. Rev. Stat. Ann. § 92:5

Official oaths may be administered as follows: To the clerk of any court, by any 2 justices thereof, or by any 2 justices of the peace; to all military officers above the rank of field officers, and to all other officers appointed by the governor and council, by any 2 members of the council, or by any member of the council with a justice of the peace, or by any 2 justices of the peace or by any justice of the peace with any notary public, or by any 2 notaries public; to all other officers, by any justice of the peace within his or her county; to town officers in town meeting, by the moderator, or at any time by the town clerk, one of the selectmen, or a justice of the peace; to officers of school districts, in school meeting, by the moderator, or at any time by the clerk, one of the school board of the district, or a justice of the peace; and to the moderator of the district, by any legal voter of the district.