To provide a handlebar mounting structure in which loosening (mechanical backlash) of a lever handlebar of a latch device provided in a door does not almost occur although a mounting part of the lever handlebar may be loosened with long-time use or the like.

In a latch device, lever handlebars 16, 17 are rotated to move a latch 13 backwards, thereby opening a door 11. In a handlebar mounting structure, the lever handlebar 17 at an inner side of the door includes a square hole 17a into which a handlebar shaft 18 having a square cross section is fitted, and a screw hole 17b communicating with the square hole 17a. In the handlebar shaft 18, a locking surface 18c is formed which opposes the screw hole 17b. Further, a pair of locking bodies 20a, 20b arrayed on the locking surface 18c are provided, and a stopper screw 21 is provided which is threaded in from the screw hole 17b and pushes the pair of locking bodies 20a, 20b in a separating direction.