[Object] Provided is a tube joining device that allows a user to easily and appropriately perform setting of tubes which become a joining target, and is capable of preventing occurrence of a joining failure caused by a setting error of the tubes in advance . [Solving Means] A tube joining device 1 includes: a first tube holding portion 41 that is capable of holding a first tube T1； a second tube holding portion 42 that is disposed in adjacent to the first tube holding portion, and is capable of holding a second tube T2 at a position that is parallel to the first tube； and a housing 2 that is provided with a cover member 20 that is closed to cover fusing-joining sites C of the first tube and the second tube. The cover member is slidable along a direction in which the first tube and the second tube are disposed in parallel.
