A joining method of metal works, comprising the steps of: providing at least one pair of metal works (1, 2), the metal works (1, 2) being configured to provide at least one gap at joining faces ( 1a, 2a) thereof when the metal works (1, 2) contact one another for joining; disposing an adhesive agent having a chain-reacting curing reaction function within said gap provided at the joining faces (1a, 2a) of the metal works ( 1, 2) contacting; performing welding at a welding portion that is located adjacently to said gap, where the metal works (1, 2) contact one another substantially directly; and applying an energy from said welding to said adhesive agent within the gap so as to generate a heat of curing reaction within the adhesive agent autogenously, wherein the pair of metal works (1, 2) are at least partly joined together by the welding applied to said welding portion and/or said adhesive agent that is cured at least by said autogenously-generated curing reaction heat caused by the welding and an additional heat that is successively generated by the autogenously-generated curing reaction heat within the adhesive agent due to the chain-reacting curing reaction function of the adhesive agent, wherein the welding is performed by radiating a laser beam for a laser welding, by a laser-beam radiation device, wherein said gap being provided by forming at least one of joining faces ( 1a, 2a) of the works (1, 2) in an uneven shape and/or wherein said gap is provided by forming at least one of joining faces (1a, 2a) of the metal works (1, 2) in a recess shape, and wherein the laser beam radiated by said laser-beam radiation device is configured so that the amount of heat applied to the welding portion for welding is greater than that applied to the adhesive agent for curing the adhesive agent, characterized in that at least one of the metal works (1, 2) has a projecting portion for at least partly accommodating said adhesive agent therein that is formed so as to project outward from said welding portion thereof, and said welding is performed on a projection side of the projecting portion of the metal work, preferably said laser beam radiation device is located on a projection side of the projecting portion of the metal work and controlled so as to radiate the laser beam at said projecting portion at least partly accommodating the adhesive agent, focusing on the welding portion, wherein the method includes a step of moving the laser beam continuously along a specified moving direction so that the welding portion of the metal work and a gap portion of the metal work that accommodates the adhesive agent are exposed to radiation of the laser beam, wherein said configuration of the laser beam is provided by differentiating the speed of moving of the laser beam from one another for the welding portion and the gap portion of the metal work. providing at least one pair of metal works (1, 2), the metal works (1, 2) being configured to provide at least one gap at joining faces ( 1a, 2a) thereof when the metal works (1, 2) contact one another for joining; disposing an adhesive agent having a chain-reacting curing reaction function within said gap provided at the joining faces (1a, 2a) of the metal works ( 1, 2) contacting; performing welding at a welding portion that is located adjacently to said gap, where the metal works (1, 2) contact one another substantially directly; and applying an energy from said welding to said adhesive agent within the gap so as to generate a heat of curing reaction within the adhesive agent autogenously, wherein the pair of metal works (1, 2) are at least partly joined together by the welding applied to said welding portion and/or said adhesive agent that is cured at least by said autogenously-generated curing reaction heat caused by the welding and an additional heat that is successively generated by the autogenously-generated curing reaction heat within the adhesive agent due to the chain-reacting curing reaction function of the adhesive agent, wherein the welding is performed by radiating a laser beam for a laser welding, by a laser-beam radiation device, wherein said gap being provided by forming at least one of joining faces ( 1a, 2a) of the works (1, 2) in an uneven shape and/or wherein said gap is provided by forming at least one of joining faces (1a, 2a) of the metal works (1, 2) in a recess shape, and wherein the laser beam radiated by said laser-beam radiation device is configured so that the amount of heat applied to the welding portion for welding is greater than that applied to the adhesive agent for curing the adhesive agent, characterized in that at least one of the metal works (1, 2) has a projecting portion for at least partly accommodating said adhesive agent therein that is formed so as to project outward from said welding portion thereof, and said welding is performed on a projection side of the projecting portion of the metal work, preferably said laser beam radiation device is located on a projection side of the projecting portion of the metal work and controlled so as to radiate the laser beam at said projecting portion at least partly accommodating the adhesive agent, focusing on the welding portion, wherein the method includes a step of moving the laser beam continuously along a specified moving direction so that the welding portion of the metal work and a gap portion of the metal work that accommodates the adhesive agent are exposed to radiation of the laser beam, wherein said configuration of the laser beam is provided by differentiating the speed of moving of the laser beam from one another for the welding portion and the gap portion of the metal work.