To provide a magnetic tape surface treatment device which is excellent in the effect of removing projections of a magnetic tape or foreign matters without removing a lubricant present on the magnetic coating film surface of the magnetic tape.

The tape surface treatment device 10 is provided with a transportation route 14, which allows the magnetic tape 12 to travel in an arrow marked F direction along its longitudinal direction, a rotating member 16 and a pair of guiding rolls 18, 18. The rotating member 16 is constituted of a cylindrical rotating body 16A and a blade 16B provided on the outer circumferential surface of the rotating body 16A. The rotating member 16 is disposed on the transporting route 14 so that the axis line of the rotating body 16A extends in a direction intersecting perpendicularly to the longitudinal direction of the magnetic tape 12 and the blade 16B is in contact with the magnetic coating film surface of the magnetic tape 12. Further, a rotary driving means, which is not shown in a figure, for rotating the blade 16B in an arrow marked (d) direction so that the moving direction of the blade 16B in contact with the magnetic coating film surface of the tape 12 is opposite to the traveling direction F of the magnetic tape 12, is provided.