An internal variable vehicle may include instrument panels provided on a side of an internal space of the vehicle, having a structure in which a portion thereof overlaps, configuring an embedding portion of the internal space when being developed, and forming an opening through which the internal space of the vehicle is externally exposed out of the vehicle when the portion thereof overlaps; a seat movable from the internal space of the vehicle to the outside; a guide provided on a floor of the internal space of the vehicle, and providing a path in which the seat is movable from the internal space of the vehicle to an opening side of the instrument panels; and a fixing module configured of fixing the seat to one point of the guide and releasing the fixing of the seat from the point of the guide when the seat is required to move to the outside of the vehicle through the opening of the instrument panels.