To provide a cover body and a file which can be easily searched and is excellent in storing efficiency even under a condition where they are displayed on a shelf or the like without any gap.

The cover body 1 has a front cover 11, a reverse cover 12 and a back cover 13, and in the cover body 1 pinching flat papers between the front cover 11 and the reverse cover 12, a connected cover body 14 is provided at a definite angle on one side of the back cover 13, and the front cover 11 being one cover among both surface papers is connected with the back cover 13 through this connected cover 14. The other side of the back cover 13 is connected with the reverse cover 12 being the other cover through a deforming part 15 which deforms changeably a gap between the front cover 11 and the reverse cover 12 in accordance with a thickness of the flat papers to be pinched.