A separating device and a method of separation are disclosed. The separating device and the method of separation are for separating a flexible substrate fixed on a carrier substrate having a first divided area and a second divided area, the flexible substrate includes an effective area defined corresponding to the first divided area and an ineffective area defined corresponding to the second divided area. The separating device comprises: a movable platen, for raising the second divided area, thereby partially separating the carrier substrate from the flexible substrate, and thereby forming a slit; a separating sheet, for separating the flexible substrate along the slit, thereby separating the effective area of the flexible substrate from the first divided area of the carrier substrate; and a suction head, for removing the separated flexible substrate from the carrier substrate.