The lock-up device includes: a clutch part disposed between a front cover and a turbine; and a damper mechanism for transmitting torque from the clutch part to the turbine and for absorbing and attenuating a torsional vibration. The damper mechanism includes: an input plate into which torque is inputted from the clutch part; an output plate connected to the turbine; a plurality of torsion springs; an intermediate member; and a restriction member. The intermediate member is rotatable relatively to the input plate and the output plate, and causes two torsion springs to act in series. The restriction member is mounted to the input plate, and restricts the intermediate member from moving in both of an axial direction and a radial direction.