Abstract: ABSTRACT OF THE DISCLOSURE: An object of the present invention is to provide a silent chain drive device that can minimize loss of strength and wear of link plates, as well as prevent the chain from lifting up to achieve better power transmission efficiency. The silent chain drive device includes a silent chain designed for inside flank meshing/inside flank seating, and a sprocket with sprocket teeth. The plurality of link plates in the silent chain, which each have a pair of teeth, are configured to make contact with the sprocket teeth only at the inside flanks of each pair of teeth when the silent chain wraps around the sprocket and meshes with all of the sprocket teeth.