Abstract: A tube unit of the present invention is a tube unit used for connecting internal equipment and external equipment, and includes an inner tube which lets liquid flow between the internal equipment and the external equipment, a cable including an electric wire connected to the internal equipment, and an outer tube which accommodates the inner tube and the cable. For the tube unit of the present invention, the expression “internal equipment” refers to a part of equipment, such as an artificial internal organ that can take the place of an internal organ of a living body or an artificial assist device that can assist the functioning of a living body, that is implanted in a living body, or equipment that is implanted in a living body by medical treatment. The expression “external equipment” can refer to equipment, out of equipment that is used as artificial internal organs, a ventricular assist device, or devices used in medical treatment, that is placed outside of a living body.