A method of manufacturing a solar cell includes the following steps. An ion implantation process is performed to a first surface of a substrate to form a first doping layer. Then, the ion implantation process is performed to a second surface of the substrate to form a second doping layer. After that, an annealing process is performed to the structure formed by the substrate, the first doping layer and the second doping layer, and forming a first passivation layer on the first doping layer and a second passivation layer on the second doping layer by the annealing process. A third passivation layer is formed on the first passivation layer formed after the annealing process and a fourth passivation layer is formed on the second passivation layer formed after the annealing process. Afterward, conductive electrodes are formed on the third passivation layer and the fourth passivation layer, respectively.