A key structure includes a key cap, a bridge assembly, a first supporting part, a second supporting part, an attractable element and a magnet. The bridge assembly includes first and second hinge parts. The first hinge part has a first pivot coupling portion and a first connecting portion. The second hinge part has a second pivot coupling portion and a second connecting portion, wherein the first and second connecting portions are connected on an axis, and the first and second hinge parts rotate with respect to the axis. The first and second supporting parts are coupled to two ends of the first and second pivot coupling portions, respectively. The attractable element is disposed on the second hinge part. The magnet is correspondingly located under the attractable element for providing a magnetic force, so that the attractable element is attracted and positioned by the magnetic force.