A soldering method using light beams and a mask for light beam shielding. The soldering method is a method for connecting a conductive line with a contact by light beams, which includes a step of arranging the conductive line in an area whereupon the contact is formed, a step of supplying a solder to the area whereupon the contact is formed, a step of arranging the mask for partially shielding the connector from light beams, and a step of connecting the conductive line with the contact by melting the solder by irradiating light beams.