Abstract: A folding knife has a handle, as well as, a first blade and a second blade, which are rotatably supported by the handle. When the first blade is located in the fold-out position and the second blade is located in the fold-in position, the first blade functions as a knife. When both the first blade and the second blade are located in the fold-out positions, the first blade and the second blade cooperate with each other so as to function as a pair of scissors. The folding knife provided merely with a pair of blades can function not only as a knife but also as a pair of scissors in spite of its simple structure. Thus, the folding knife is reduced in number of parts and is simplified in structure.