Abstract: A flat-type torque converter wherein a toroid is formed of a turbine having a plate-worked turbine blade, a pump having a plate-worked pump blade and a stotor having a cast-iron stator blade, and a ratio L.sub.1 /(r.sub.2 --r.sub.1) of a toroid axial dimension L.sub.1 to its radial dimension (r.sub.2 --r.sub.1) lines between 0.67 and 0.87, a ratio r.sub.1 /r.sub.2 of a toroid internal radius r.sub.1 to its external radius r.sub.2 lies between 0.39 and 0.46, and the converter has a small axial thickness; characterized by that a wall thickness of the stator blade is made small so that an effective passage cross section inside the stator blade can be secured, a flow-in side tip edge of the stator blade is formed into a flat-shape, a core-side and a shell-side of the stator blade are formed by being twisted, and a core-side length of the stator blade is fabricated as long as possible.