A detachment apparatus having an arched drum pad and a method for fabricating a lightweight, thin liquid crystal display (LCD) device using the same are provided. The detachment apparatus includes: a table to which an object to be processed is loaded; an arched drum pad installed over the table and including O-rings formed on a lower surface thereof and a plurality of vacuum compartments demarcated by the O-rings; and a plurality of driving units configured to control a position of the drum pad. In case of using an auxiliary substrate to perform a process of a thin glass substrate, the auxiliary substrate can be easily separated from a liquid crystal panel in a cell state attached after processes are completed by using the arched drum pad having O-rings and a plurality of vacuum compartments.