Abstract: A support member includes: a pair of first support members provided to sandwich and support an attachment portion, one of the first support members being in contact with a vehicle side; and a second support member provided between the pair of first support members, formed separately from the first support members, and configured to support an inner peripheral side of a through hole. An attachment portion is provided at the other end portion of a plate spring member having one end portion fixed to a catalyst converter, and vibration applied to the catalyst converter is absorbed by elastic deformation of the plate spring member. Vibration in a thickness direction of the plate spring member is absorbed by elastic deformation of the first support members, and vibration in a longitudinal direction of the plate spring member is absorbed by elastic deformation of the second support member.