Make sure the blade is dry when not in use. A couple of shakes after rinsing will keep it from rusting. Let it sit out to air dry.
It’s good to oil the blade once in awhile. Just put a couple of drops of oil on a paper towel and carefully wipe the blade from edge to edge on both sides. Wipe off any excess if necessary.
If rust occurs put a few drops of cooking oil on the blade and peel a potato or carrot.
You also may remove rust using steel wool. Be very careful as the blade is extremely sharp. The blade will be just as sharp as it was.