A Device for gripping and welding solar cells with corresponding electrical connector for the construction of a string of solar cells, comprising: - suction means able to hold during use the solar cell or the electrical connector and defining a gripping area of said solar cell or of said electrical connector; - welding means of said electrical connector to said solar cell and defining a welding area of said electrical connector, able to heat during use said welding area for melting said electrical connector; and being characterised in that: said suction means are movable with respect to said welding means between a gripping position, wherein said suction means retain said solar cell or said electrical connector spaced from said welding area, and a welding position, wherein said suction means retain said electrical connector at said welding area in contact with said welding means during the melting of the welding layer of said electrical connector, and wherein said suction means and said welding means are aligned along an alignment axis parallel to said gripping area and to said welding area in said welding position; wherein said suction means consist of two suction ducts aligned along said alignment axis, wherein said device for gripping and welding comprises elastic means operatively connected to said suction ducts for moving said suction ducts between said gripping position and said welding position, and vice versa, wherein said elastic means are pre-tensioned to keep said suction ducts in said gripping position and allow said suction ducts to be arranged in said welding position when said suction ducts are subjected to pressure on a support, wherein said welding means comprise a welding tip which defines said welding area, wherein said suction ducts and said welding tip are aligned along said alignment axis in said welding position, and wherein said welding tip is arranged side by side with said suction ducts. - suction means able to hold during use the solar cell or the electrical connector and defining a gripping area of said solar cell or of said electrical connector; - welding means of said electrical connector to said solar cell and defining a welding area of said electrical connector, able to heat during use said welding area for melting said electrical connector; said suction means are movable with respect to said welding means between a gripping position, wherein said suction means retain said solar cell or said electrical connector spaced from said welding area, and a welding position, wherein said suction means retain said electrical connector at said welding area in contact with said welding means during the melting of the welding layer of said electrical connector, and wherein said suction means and said welding means are aligned along an alignment axis parallel to said gripping area and to said welding area in said welding position; wherein said suction means consist of two suction ducts aligned along said alignment axis, wherein said device for gripping and welding comprises elastic means operatively connected to said suction ducts for moving said suction ducts between said gripping position and said welding position, and vice versa, wherein said elastic means are pre-tensioned to keep said suction ducts in said gripping position and allow said suction ducts to be arranged in said welding position when said suction ducts are subjected to pressure on a support, wherein said welding means comprise a welding tip which defines said welding area, wherein said suction ducts and said welding tip are aligned along said alignment axis in said welding position, and wherein said welding tip is arranged side by side with said suction ducts.