To provide a texture device and its method capable of a superior CSS characteristic, sticking characteristic, and low floating of a magnetic head simultaneously.

A laser beam outputted from a laser beam generator 1 is emitted on a substrate 6 through a modulator 2, polarizing beam splitter 3, 1/4λ plate 4, mirror 5a, and a condensing mechanism 5. This substrate 6 is rotated by a substrate rotating mechanism 7, the modulator 2 is ON/OFF-controlled by a timing controller 11, the condensing mechanism 5 is moved in the radial direction of the substrate 6 by a transfer mechanism 12, and the substrate is thereby texture-processed. Reflection light from the substrate 6 is returned to the polarizing beam splitter 3 through the condensing mechanism 5, mirror 5a and, 1/4λ plate 4, reflected by a prism mating face, and received by a light receiving system 9, with the reflected light quantity monitored by a monitoring device 10 for reflected light. Incident light passing through the modulator 2 is monitored by a monitoring device 8 for incident light.