To provide high rigidity of an elastic float body made of an elastic resin material.

An elastic float body 80 is used in a damper mechanism for absorbing and damping the vibration in the direction of rotation of a rotary member. The elastic float body 80 is provided with a main body 81 and a seat part 82. The main body 81 is made of an elastic resin material and is long in one direction. The seat part 82 is fixed to both ends in the longitudinal direction of the main body 81. The seat part 82 is a highly rigid member having a larger diameter than the main body 81 and higher rigidity than the main body 81.