A sterilization module including a light source configured to irradiate ultraviolet light, a board on which the light source is mounted, a protective tube accommodating the board therein and configured to transmit ultraviolet light irradiated from the light source, a first base coupled to one side of the protective tube, and a second base coupled to the other side of the protective tube, in which at least one of the first base and the second base includes an insertion part to be inserted into the protective tube, the insertion part having a first diameter when viewed in a first cross-section perpendicular to a length direction of the protective tube, and a cover part integrally formed on the insertion part and having a second diameter greater than the first diameter in the first cross-section.