PURPOSE: An adhesive tape, prepared by forming many flaws irregularly arranged along the selvedges thereof in the long direction, and capable of being cut only tearing off with fingers without using a cutter with a very little deterioration in the strength.

CONSTITUTION: A broad tape material is wound in the form of a roll, and cut in round slices by a circular cutter 1 having a blade 2 on the circumference and a file surface having abrasive grains 4 on both sides to a given width. Thus, the aimed tape, having many flaws irregularly arranged along the selvedges in the long direction thereof, and capable of being roughened on the slit surfaces 8 simultaneously with the cutting. The slit surfaces 8 may be ground by an emery paper in the radial direction. The flaws have such a depth as to give a tear starting effect in the transverse direction of the tape, and the flaws are preferably present in a ratio of one or more per 0.2cm length.