A building structure that can be assembled easily with high assembling precision is provided.
The building structure of the present invention is a building structure for transmitting a load on a roof to a post, and includes a unit (10) joined to a post (20). The unit includes three or more first beams arranged in parallel in one direction and three or more second beams arranged in parallel in another direction intersecting the one direction. Each first beam and each second beam has a truss structure. In a section where the first beam intersects the second beam, an upper chord of the first beam is disposed on an upper chord of the second beam and is joined to the upper chord of the second beam via a joining member, using a fastener. In the section where the first beam intersects the second beam, a lower chord of the first beam is disposed on a lower chord of the second beam and is joined to the lower chord of the second beam via a joining member, using a fastener.