A substrate fixing jig assembly includes a carrier having a substrate fixing jig insertion recess, a substrate fixing jig removably inserted into the substrate fixing jig insertion recess and having a substrate accommodating portion, and a substrate support portion slidably provided on the substrate fixing jig and fixing a substrate accommodated in the substrate accommodating portion.

A membrane device includes a vacuum device main body having a plurality of vacuum holes such that a real wood sheet to be temporarily attached to a core is mounted in the vacuum device main body, a cover having a silicone film to define a vacuum space together with the vacuum device main body, a vacuum module to suck air in the vacuum device main body through the vacuum holes, and a control unit to compress the real wood sheet and the core for a preset time by sucking air in the vacuum space through the vacuum holes. The control unit removes the vacuum from the vacuum space by controlling the vacuum module so that the compressed real wood sheet is detached, and the vacuum device main body includes sliders to perform wrapping the real wood sheet around the inside of the core while moving upward.