In small saucepan over low heat, slowly melt butter; do not stir. Remove from heat.
Skim white foam off of top and discard. Let remaining butter stand 2 minutes to allow milk solids to fall to the bottom. Carefully pour the golden layer (clarified butter) into a separate dish, being careful to stop before pouring out thick bottom layer (milk solids); discard bottom layer.
Keep clarified butter warm until ready to use or refrigerate, covered, up to 1 month.