The present invention relates to a horizontal double side grinding machine which grinds both sides of a structure. A grinding unit is individually installed on both sides of a frame, and a structure guide rail is installed in the center of the frame. A structure fixing unit fixing a plurality of the structures is arranged on the structure guide rail. The structure fixing unit is moved forwards and backwards from the frame along the structure guide rail by a structure moving screw rotated by a structure moving motor. A structure input unit inputting a plurality of the structure into the structure fixing unit located on an inlet of the structure guide rail is installed on one side of the frame. A structure discharge unit discharging structures of the structure fixing unit located on an outlet of the structure guide rail is installed on the other side of the frame.
