A work holding mechanism for horizontally holding a flat work is incorporated in work transport equipment. The holding mechanism includes a base member for supporting the work and a plurality of guide members provided at the base member. Each guide member includes a shaft, a contact portion and a limit portion. The shaft is pivotally supported by the base member. The contact portion comes into contact with part of the lower surface of the perimeter of the work and is pushed down, with the shaft as a fulcrum, when the work is placed on the base member. The limit portion is raised, with the shaft as a fulcrum, to face part of the side surface of the perimeter of the work when the contact portion is lowered.