To provide an energy absorbing device, a seat belt retractor, and a seat belt apparatus that can vary an energy absorbing amount depending on increase and decrease of rotation speed between relatively rotating objects and can improve durability. An energy absorbing device includes a casing connected to one object, an annular first clutch disc disposed in the casing, an annular second clutch disc disposed in the casing, and an annular clutch plate connected to the other object and having an engaging surface that faces both the first clutch disc and the second clutch disc, wherein the engaging outer teeth of the first clutch disc and the engaging inner teeth of the second clutch disc alternately engage with the engaging teeth of the clutch plate so as to absorb an energy generated by a relative rotation between one object and the other object.