Materials:
Sulfuric acid conc. (H2SO4)
Potassium nitrate (KNO3)
or sodium nitrate (NaNO3)
or calcium nitrate (Ca(NO3)2)

When making nitric acid you gotta have right equipment, or else it will be dangerous and messy. Set up equipment for basic distillation, all equipment must be made of glass or other inert material (for example teflon).

Place any nitrate salt (for example KNO3) in distilling vessel, add enough sulfuric acid (H2SO4) to cover the salt. Heat reaction mixture to 100oC and then, gradually, to 120oC. Warning, this should be made in good ventilated area (reaction will produce some NOx gases).
Reaction is considered complete when reaction mixture becomes slightly yellow and nitric acid stops condensing.