The present invention relates to a therapeutic substance delivery device for delivering a therapeutic substance to a desired site in a bodily duct, characterized in that the therapeutic substance delivery device is provided with: a therapeutic substance loading portion； a connector which is connected to the therapeutic substance loading portion； and a supplying/discharging pipe connected to the connector； and in that the therapeutic substance loading portion includes a main body portion in which a recessed portion is formed, a resilient film, and a connecting pipe； the connector is provided with a joint main body, a flange portion fixed to the other end portion side of the joint main body, and a fixing nut through which the joint main body passes； the joint main body is provided with a tube fastening portion； and at least part of the inner wall of the fixing nut is provided with a thread.
