A torque fluctuation absorber includes a center plate rotatably arranged, a side plate arranged coaxially with and rotatably relative to the center plate, an elastic member accommodated in a space surrounded by the side plate and absorbing torque fluctuations generated between the side plate and the center plate, a cover member separating the space and an outside space from each other by covering a clearance between the center plate and the side plate, and a vent portion arranged inwardly in a radial direction of the side plate relative to the cover member and providing a ventilation between the space and the outside space.