Just plug in with an HTML cord (included) and push the "Sanitize" button ONCE. It will chirp and does not look like it is doing anything. But in about 15-20 minutes it will chirp again to indicate it is finished. Optional: you can add a few drops of scented oil on the strip inside the unit. If you press the "aroma" button it will blow through the oil to provide a slight fragrance. It did not come with a manual but I was able to find some instructions online.