A rivet nut unit is disclosed. An exemplary embodiment of the present invention provides a rivet nut unit bonding at least one plate by being riveted to the plate and fastened with a bolt that may include: a head portion supported on an upper surface of the plate at a position corresponding to a processed hole in the plate, and formed with a penetration hole in the middle thereof corresponding to the hole; and an insertion portion extended from one side of the head portion, inserted into the hole, and formed with at least one slot and a protruding end bent to a lower surface of the plate for coupling the head portion to the plate while riveting the plate.