MEDICAL DEVICE

A medical device includes: a sheath that is provided with a flexible section configured to have flexibility so as to be deformed between a first shape extending along the longitudinal axis and a second shape bent in a direction intersecting the longitudinal axis; a deformation assisting member attached to the sheath so as to be movable along a surface of the sheath; a position adjustment part connected to a proximal end section of the sheath, the position adjustment part being configured to adjust a relative position of the deformation assisting member with respect to the sheath; and a curved section provided at one of the flexible section and one longitudinal section of the deformation assisting member and having a bent shape. The deformation assisting member disposed at the flexible section imparts to the flexible section a driving force for causing deformation between the first shape and the second shape.