A substrate transferring device is disclosed. In one aspect, the substrate transferring device includes substrate to transfer the substrate in one direction and a plurality of side rollers. Each roller includes a side roller main body configured to rotate while contacting a side surface of the substrate to prevent the substrate from being deviated from the one direction. The roller also includes a side roller support which is coupled to a lower part of the side roller main body or a lower part of the side roller main body when the side roller main body is turned upside down in a vertical direction to vary a position of a contact line where the side surface of the substrate is in contact with the side roller main body. The roller further includes a fixing member which is coupled to the side roller support inside the side roller main body.