A rebar tying tool configured to tie plural rebars using a wire is disclosed herein. The rebar tying tool may include a reel supporting mechanism configured to switch between a first state of detachably supporting a reel on which the wire is wound and a second state of undetachably supporting the reel; a wire feeding mechanism configured to feed the wire from the reel; and an openable cover that at least partially covers at least one of the reel supporting mechanism and the wire feeding mechanism. The reel supporting mechanism may switch from the first state to the second state by a user operation of closing the cover, and/or may switch from the second state to the first state by a user operation of opening the cover.