A thermal treatment device, used for performing a thermal treatment on an absorbing layer precursor on a substrate of a solar cell, the absorbing layer precursor containing copper, zinc, tin and sulfur, the thermal treatment device comprising: a first chamber having a base, and the substrate being disposed on the base; a carrier, wherein a solid-phase vapor source is disposed on the carrier, the carrier is adapted for selectively moving with the solid-phase vapor source in the first chamber to maintain a predetermined distance between the solid-phase vapor source and the absorbing layer precursor, a temperature controller assembled in the first chamber, wherein the temperature controller is adapted for adjusting the temperature in the first chamber; characterized in that the solid-phase vapor source contains tin and characterized by a controller, wherein the controller is adapted for controlling the carrier to move with the solid-phase vapor source according to the temperature in the first chamber; and a load-locking unit and a second chamber, wherein the load-locking unit is connected with the first chamber and the second chamber, the controller is adapted for controlling the load-locking unit and the carrier, so that the carrier moves with the solid-phase vapor source from the first chamber through the load-locking unit to the second chamber or the carrier moves with the solid-phase vapor source from the second chamber through the load-locking unit to the first chamber according to the temperature in the first chamber. a first chamber having a base, and the substrate being disposed on the base; a carrier, wherein a solid-phase vapor source is disposed on the carrier, the carrier is adapted for selectively moving with the solid-phase vapor source in the first chamber to maintain a predetermined distance between the solid-phase vapor source and the absorbing layer precursor, a temperature controller assembled in the first chamber, wherein the temperature controller is adapted for adjusting the temperature in the first chamber; characterized in that the solid-phase vapor source contains tin and characterized by a controller, wherein the controller is adapted for controlling the carrier to move with the solid-phase vapor source according to the temperature in the first chamber; and a load-locking unit and a second chamber, wherein the load-locking unit is connected with the first chamber and the second chamber, the controller is adapted for controlling the load-locking unit and the carrier, so that the carrier moves with the solid-phase vapor source from the first chamber through the load-locking unit to the second chamber or the carrier moves with the solid-phase vapor source from the second chamber through the load-locking unit to the first chamber according to the temperature in the first chamber. a controller, wherein the controller is adapted for controlling the carrier to move with the solid-phase vapor source according to the temperature in the first chamber; and a load-locking unit and a second chamber, wherein the load-locking unit is connected with the first chamber and the second chamber, the controller is adapted for controlling the load-locking unit and the carrier, so that the carrier moves with the solid-phase vapor source from the first chamber through the load-locking unit to the second chamber or the carrier moves with the solid-phase vapor source from the second chamber through the load-locking unit to the first chamber according to the temperature in the first chamber.