A method for suppressing galvanic corrosion of a metal component, by preventing a contact between a composite material part main body and said metal component, the method comprising the step of applying an insulating layer to the faces of the composite material part main body, applying insulative coating to a carbon-fiber exposed end of a composite material part including the composite material part main body and the insulating layer using a dispenser device, the dispenser device comprising a first tank configured to store a first material, a second tank configured to store a second material, a mixing nozzle configured to mix the first material and the second material to form a mixed material, and to discharge the mixed material obtained by mixing the first material and the second material, a first channel arranged between the first tank and the mixing nozzle, a second channel arranged between the second tank and the mixing nozzle, a first flow regulator arranged on the first channel and configured to regulate flow of the first material, a second flow regulator arranged on the second channel and configured to regulate flow of the second material, and a control unit configured to control the first flow regulator and the second flow regulator, wherein the application of the insulative coating to the carbon-fiber exposed end of the composite material part comprises: a mixing step for mixing the first material and the second material in the mixing nozzle and forming the mixed material, a discharging step for discharging the mixed material from the mixing nozzle toward the carbon-fiber exposed end; and a coating step for applying the mixed material discharged from the mixing nozzle to the carbon-fiber exposed end such that the carbon-fiber exposed end is covered with the insulative coating, wherein the first material is a resin material in liquid state and is an electrical insulating material, the second material is a resin material in liquid state and is an electrical insulating material, and the second material is a material that differs from the first material. applying an insulating layer to the faces of the composite material part main body, applying insulative coating to a carbon-fiber exposed end of a composite material part including the composite material part main body and the insulating layer using a dispenser device, the dispenser device comprising a first tank configured to store a first material, a second tank configured to store a second material, a mixing nozzle configured to mix the first material and the second material to form a mixed material, and to discharge the mixed material obtained by mixing the first material and the second material, a first channel arranged between the first tank and the mixing nozzle, a second channel arranged between the second tank and the mixing nozzle, a first flow regulator arranged on the first channel and configured to regulate flow of the first material, a second flow regulator arranged on the second channel and configured to regulate flow of the second material, and a control unit configured to control the first flow regulator and the second flow regulator, wherein the application of the insulative coating to the carbon-fiber exposed end of the composite material part comprises: a mixing step for mixing the first material and the second material in the mixing nozzle and forming the mixed material, a discharging step for discharging the mixed material from the mixing nozzle toward the carbon-fiber exposed end; and a coating step for applying the mixed material discharged from the mixing nozzle to the carbon-fiber exposed end such that the carbon-fiber exposed end is covered with the insulative coating, wherein the first material is a resin material in liquid state and is an electrical insulating material, the second material is a resin material in liquid state and is an electrical insulating material, and the second material is a material that differs from the first material. a mixing step for mixing the first material and the second material in the mixing nozzle and forming the mixed material, a discharging step for discharging the mixed material from the mixing nozzle toward the carbon-fiber exposed end; and a coating step for applying the mixed material discharged from the mixing nozzle to the carbon-fiber exposed end such that the carbon-fiber exposed end is covered with the insulative coating, wherein the first material is a resin material in liquid state and is an electrical insulating material, the second material is a resin material in liquid state and is an electrical insulating material, and the second material is a material that differs from the first material.