A protecting module for coupling, in use, to a laser welding device, the laser welding device comprising a main housing, a protective glass and an optical system housing for supporting the protective glass, wherein, in operation the laser welding device provides a laser beam which passes through the protective glass, the protecting module comprising: a first cover having an aperture for allowing, in use, a laser beam to pass therethrough; a second cover which is, in use, provided on one side of a main housing of the laser welding device in a coupled state with the first cover, is couplable to the optical system housing and when so-coupled is located on one side of a main housing, and has an aperture that allows, in use, the laser beam to pass therethrough; and a plurality of air supply units which are installed on an outer circumferential surface of the first cover or the second cover and through which outside air flows into, wherein the first cover or the second cover comprises an air flow path, said air flow path being a channel which is recessed from a plate surface on one side of the first cover or the second cover and a plurality of air holes which pass therethrough to allow the air flow path and the outer circumferential surface of the first cover or the second cover to be in fluid communication with each other, and the air supply units are in fluid communication with the air holes, wherein the air supply units are configured to supply air to the air flow path, such that it is, in use, discharged to a space A space between mating surfaces of the first cover and the second cover and toward the apertures, wherein the first cover and the second cover have a disc shape, and the air flow path has a ring shape and is provided in the plate surface of the first cover or the second cover, and characterised in that the protecting module further comprises a reflected light-absorbing plate which is coupled to a plate surface of the first cover on the opposite side from the second cover, has a hole which allows the laser beam, in use, beam to pass therethrough, and has black color, wherein the reflected light-absorbing plate has a disc shape and has a plurality of streamline-shaped plate slits which pass therethrough and are spaced apart from each other along an outer edge. a first cover having an aperture for allowing, in use, a laser beam to pass therethrough; a second cover which is, in use, provided on one side of a main housing of the laser welding device in a coupled state with the first cover, is couplable to the optical system housing and when so-coupled is located on one side of a main housing, and has an aperture that allows, in use, the laser beam to pass therethrough; and a plurality of air supply units which are installed on an outer circumferential surface of the first cover or the second cover and through which outside air flows into, wherein the first cover or the second cover comprises an air flow path, said air flow path being a channel which is recessed from a plate surface on one side of the first cover or the second cover and a plurality of air holes which pass therethrough to allow the air flow path and the outer circumferential surface of the first cover or the second cover to be in fluid communication with each other, and the air supply units are in fluid communication with the air holes, wherein the air supply units are configured to supply air to the air flow path, such that it is, in use, discharged to a space A space between mating surfaces of the first cover and the second cover and toward the apertures, wherein the first cover and the second cover have a disc shape, and the air flow path has a ring shape and is provided in the plate surface of the first cover or the second cover, and characterised in that the protecting module further comprises a reflected light-absorbing plate which is coupled to a plate surface of the first cover on the opposite side from the second cover, has a hole which allows the laser beam, in use, beam to pass therethrough, and has black color, wherein the reflected light-absorbing plate has a disc shape and has a plurality of streamline-shaped plate slits which pass therethrough and are spaced apart from each other along an outer edge.