An X-ray metal grating structure of the present invention has a grating region in which a plurality of first structural portions are periodically provided, wherein an air gap is formed between each of the plurality of first structural portions and a second structural portion as a remaining part of the grating region other than the plurality of first structural portions. Thus, the X-ray metal grating structure of the present invention is formed as a grating structure having high flatness. A production method therefor comprises a step of forming the air gap between the first structural portion and the second structural portion. Thus, the production method makes it possible to produce an X-ray metal grating structure having high flatness. The present invention further provides an X-ray metal grating unit and an X-ray imaging device each comprising the X-ray metal grating structure.
