A support structure includes: a support frame as a shaft support member for supporting two shafts; a bush provided on each of the two shafts in a slidable manner; a cover support member connected to the multiple bushes and configured to support the cover; a first connection member for connecting one end of each of the two shafts to the support frame in a manner that the relative position between the shaft and the support frame will not change; and a second connection member for connecting the other end of each of the two shafts to the support frame in a manner that the relative position between the shaft and the support frame can change.