PURPOSE: To improve the durability of a magnetic tape by defining the cut surface containing less cracks out of two surfaces of a magnetic tape as a guide band side when the magnetic tape is wound around a magnetic recording/reproducing device having a guide band and performing the recording or reproducing operation.

CONSTITUTION: A magnetic tape T2 is wound around a magnetic recording/ reproducing device with its cut surface turned down, i.e., defined as the guide band side. At the same time, the lengthwise direction of the tape T2 is cut so that the end I is set toward the driving direction (coating side). Thus the tape T2 is driven so that the reproduction output of a magnetic head 3 is increased. At the same time, the cut surface having less cracks out of two cut surfaces of the tape T2 is set along the guide band. Thus it is possible to improve the durability of a magnetic tape and to perform the video recording/reproducing operation with high picture quality.