Provided is a fishing reel equipped with an anti-loosening handle. The fishing reel includes an anti-loosening plug that is fitted on first flat portions of a handle shaft and has sub-male threaded portions corresponding to first male threaded portions in order to solve a problem that a handle nut is loosened or a handle shaft is broken when a load is applied to a handle arm in a process of winding a fishing line due to a gap between the handle nut and a flat portion of a handle shaft even though the handle nut is fixed in common handle shafts having an anti-idling flat portion at an end which is formed by U-cutting or side-cutting to couple the handle arm without idling.
