To lower the coefficient of static friction of the circumferential surface of the guide or drum constituting the magnetic tape apparatus. A flat portion is formed between peak portions. The peak portions and flat portion are formed so that the relationship: a'<a is satisfied, where "a" represents a distance between the ridges of the peak portions, i.e., pitch of the peak portions, and "a'" represents a bottom width of the peak portions. When this relationship is satisfied between the peak portions and the flat portion, the total area of the meniscuses formed between the magnetic tape and the peak portions can be reduced, thus making it possible to lower the coefficient of static friction.
