To provide a shelf device that can install a shelf at an arbitrary height without being restricted by pitches of engagement holes formed in a support post and also improves the workability of installation of the shelf.

The shelf device 2 is configured such that the shelf 4 is installed to the support post 7 in which a plurality of engagement holes 15 are disposed vertically. The shelf device includes an engagement member 27 that is provided in the shelf 4 and is configured to be freely projectable and retractable in a direction from the shelf 4 to the engagement hole 15. The engagement member 27 enters the engagement hole 15 while projecting from the shelf 4, the shelf 4 is then installed to the support post 7 in the state, and also while the engagement member 27 is retracted, the engagement member 27 is positioned outside the engagement hole 15.