To clean and maintain a leather briefcase:nn1. Wipe off any dust or dirt using a soft cloth or brush.n2. Use a leather cleaner or mild soap mixed with water to gently clean the surface.n3. Apply a leather conditioner to keep the leather moisturized and prevent it from drying out.n4. Store the briefcase in a cool, dry place when not in use.n5. Avoid exposure to direct sunlight or extreme temperatures, as they can damage the leather.