A medical device is disclosed for delivering a medical member which is intended to indwell in a treatment site of a urethra includes a flexible main body that extends in an axial direction, a balloon that includes an effectively dilatable portion on which the medical member is mounted, that has a dilating space into which a pressurizing medium flows between an outer surface of the main body and the balloon, and that is capable of dilating deformation and deflating deformation, an elongated guide member that is arranged across the treatment site and the outside of a living body via the urethra, and an attachment portion to which at least a portion of the guide member is detachably attached at a position between both end portions in the axial direction of the main body.
