Remove prime rib from refrigerator and allow the meat to come to room temperature, about 3 hours (depending upon the size of the roast).

Preheat oven to 425 degrees F. Line a roasting pan with aluminum foil.

Unwrap the roast and place onto roasting pan; blot with paper towels. Sift together flour, pepper, salt, paprika, onion powder, garlic powder and celery seed into a small bowl. Coat the roast all over with the flour mixture.

Roast in preheated oven for 15 minutes at 400 degrees.

Then continue cooking in a 325 degree oven to your desired degree of doneness; about 4 1/2 hours (20 minutes per pound) for medium-rare.

Roast to an internal temperature of:

120 degrees F for medium-rare.

130 degrees F for medium

140 degrees F for well done

When the roast has finished cooking, take it out of the oven, and cover with aluminum foil. Allow to rest in a warm spot for 30 minutes to 1 hour before slicing.