Copper is an important material in order to use electricity effectively, and aluminum is also attractive material to perform lightweight construction. Laser welding of copper and aluminum has been required, and there are some reports to weld copper and aluminum firmly by laser irradiation from aluminum side. On the other hand, the laser irradiation from copper side requires high power density to generate a keyhole, which causes the strong convection of molten aluminum into copper. Thus, brittle intermetallic compounds IMC with aluminum rich results in the deterioration of joining strength. The angled laser irradiation enables mild heat input to aluminum aide, and the combination of angled and superposed irradiation of blue and IR lasers achieved the remarkable increase of breaking strength in cross tensile test by 80%. However, the breaking strength is still lower than base materials, and the further improvement is necessary. Therefore, insert metals between copper and aluminum plate were investigated by angled irradiation of blue and IR lasers from copper side. The breaking strength with insert metals showed higher values in order of Ti mesh, Ni sheet, and Ni mesh insert, and its value with Ni mesh was close to tensile strength of aluminum in cross tensile test. Further improvement of breaking strength is possible by inserting Ni-mesh between Cu and Al plates in the case of angled irradiation of blue and NIR lasers even from copper side.