PURPOSE: To form microscopic holes having adhesiveness and having a bulged flange whose life is improved by regulating the ratio of the dimension of the microscopic hole measured along the periphery of a cylinder to the dimension measured in parallel to the longitudinal axis of the cylinder to ≥ the specified value.

CONSTITUTION: The continuous laser beam flux 32 radiated from an emitter 33 is intermitted by shredding it with a perforated disk 35, this intermittent laser beam is transmitted to a marking head 42 and the laser beam flux is faced to the surface of the cylinder 40 of a rolling mill. The disk 35, cylinder 40 and feed screw 45 are rotated through a distributing mechanism for adequately synchronizing them with a motor 46. In the case of the disk where the width of an opening part is equal to the distance between the opening parts, the circular microscopic holes which are regularly arranged are obtained. At this time, the ratio L/l of the dimension L of the microscopic hole which is measured along the periphery 40 of the cylinder to the dimension (l) of the microscopic hole which is measured in parallel to the longitudinal axis of the cylinder is set to ≥1, preferably, to <5.