A prefabricated wall for interior use which partitions an indoor space of a building, the prefabricated wall comprising: a runner installed to face a ceiling and a floor; a plurality of studs vertically installed and fixed on both sides of the runner in a widthwise direction; and a finishing panel coupled to the plurality of studs, wherein each of the plurality of studs are provided with a pair of coupling grooves that are configured to extend in parallel to each other in a lengthwise direction, the finishing panel is provided with a pair of elastic coupling members which are fixedly coupled to both ends of left and right sides of an inner side surface of the finishing panel so as to extend in a vertical direction, and each of the pair of coupling grooves is provided on its left and right inner side surfaces with one or more stopping protrusion extending in a lengthwise direction, wherein each of the pair of elastic coupling members comprises a contact portion that adheres to the inner side surface of the finishing panel, and a protruding portion that is configured to protrude from the contact portion in an inward direction and extend in a lengthwise direction, wherein the protruding portion is provided on its central portion with a separation groove that forms concavely in a lengthwise direction such that a left side coupling piece and a right side coupling piece are formed on left and right sides of the separation groove, wherein one or more coupling projection is formed to extend in a lengthwise direction on a left side surface of a left side coupling piece and a right side surface of a right side coupling piece so as to be fast with the one or more stopping protrusion, wherein each of the pair of elastic coupling members further comprises a panel side finishing wing portion that is bent from one end of the contact portion so as to encompass a side surface portion of the finishing panel and is configured to extend in a lengthwise direction, wherein the finishing panel is installed on a front surface portion of the plurality of studs by inserting and coupling the protruding portions of the elastic coupling members into the coupling grooves characterized in that the prefabricated wall further comprises an elastic piece that is configured to extend in a lengthwise direction with a "U" shaped section in order to prevent a reduction in a restoring force of the left side coupling piece and the right side coupling piece by inserting into the separation groove; and in that the elastic piece is coupled, so as to extend in a vertical direction, to both ends of left and right sides of the inner side surface of the finishing panel, with the pair of elastic coupling members in a state that the elastic piece is inserted into the separation groove, whereby each of the pair of elastic coupling members is fixed to the finishing panel. a runner installed to face a ceiling and a floor; a plurality of studs vertically installed and fixed on both sides of the runner in a widthwise direction; and a finishing panel coupled to the plurality of studs, wherein each of the plurality of studs are provided with a pair of coupling grooves that are configured to extend in parallel to each other in a lengthwise direction, the finishing panel is provided with a pair of elastic coupling members which are fixedly coupled to both ends of left and right sides of an inner side surface of the finishing panel so as to extend in a vertical direction, and each of the pair of coupling grooves is provided on its left and right inner side surfaces with one or more stopping protrusion extending in a lengthwise direction, wherein each of the pair of elastic coupling members comprises a contact portion that adheres to the inner side surface of the finishing panel, and a protruding portion that is configured to protrude from the contact portion in an inward direction and extend in a lengthwise direction, wherein the protruding portion is provided on its central portion with a separation groove that forms concavely in a lengthwise direction such that a left side coupling piece and a right side coupling piece are formed on left and right sides of the separation groove, wherein one or more coupling projection is formed to extend in a lengthwise direction on a left side surface of a left side coupling piece and a right side surface of a right side coupling piece so as to be fast with the one or more stopping protrusion, wherein each of the pair of elastic coupling members further comprises a panel side finishing wing portion that is bent from one end of the contact portion so as to encompass a side surface portion of the finishing panel and is configured to extend in a lengthwise direction, wherein the finishing panel is installed on a front surface portion of the plurality of studs by inserting and coupling the protruding portions of the elastic coupling members into the coupling grooves characterized in that the prefabricated wall further comprises an elastic piece that is configured to extend in a lengthwise direction with a "U" shaped section in order to prevent a reduction in a restoring force of the left side coupling piece and the right side coupling piece by inserting into the separation groove; and in that the elastic piece is coupled, so as to extend in a vertical direction, to both ends of left and right sides of the inner side surface of the finishing panel, with the pair of elastic coupling members in a state that the elastic piece is inserted into the separation groove, whereby each of the pair of elastic coupling members is fixed to the finishing panel.