A method for manufacturing a solar cell, the method comprising: conductive region formation of forming a first-conduction-type region at one surface of a semiconductor substrate and a second-conduction-type region at another surface of the semiconductor substrate; and electrode formation of forming a first electrode connected to the first-conduction-type region and a second electrode connected to the second-conduction-type region, wherein, in the conductive region formation, the first-conduction-type region is formed by forming a dopant layer containing a first-conduction-type dopant over the one surface of the semiconductor substrate, and heat-treating the dopant layer, and the second-conduction-type region is formed by ion-implanting a second-conduction-type dopant into the semiconductor substrate at the other surface of the semiconductor substrate, wherein the conductive region formation further comprises: forming the second-conduction-type region through ion implantation of the second-conduction-type dopant into the semiconductor substrate at the other surface of the semiconductor substrate; forming a capping film over the second-conduction-type region; forming the dopant layer containing the first-conduction-type dopant over the one surface of the semiconductor substrate after formation of the capping film; diffusing the first-conduction-type dopant through heat treatment, thereby forming the first-conduction-type region; wherein the formation of the capping film and the formation of the dopant layer are carried out through an in-situ process, wherein the formation of the capping film is carried out using a raw gas comprising an oxygen gas and a silicon-containing gas; and the formation of the dopant layer is carried out using the oxygen gas, the silicon-containing gas, and a dopant-containing gas containing the first-conduction-type dopant. conductive region formation of forming a first-conduction-type region at one surface of a semiconductor substrate and a second-conduction-type region at another surface of the semiconductor substrate; and electrode formation of forming a first electrode connected to the first-conduction-type region and a second electrode connected to the second-conduction-type region, wherein, in the conductive region formation, the first-conduction-type region is formed by forming a dopant layer containing a first-conduction-type dopant over the one surface of the semiconductor substrate, and heat-treating the dopant layer, and the second-conduction-type region is formed by ion-implanting a second-conduction-type dopant into the semiconductor substrate at the other surface of the semiconductor substrate, wherein the conductive region formation further comprises: forming the second-conduction-type region through ion implantation of the second-conduction-type dopant into the semiconductor substrate at the other surface of the semiconductor substrate; forming a capping film over the second-conduction-type region; forming the dopant layer containing the first-conduction-type dopant over the one surface of the semiconductor substrate after formation of the capping film; diffusing the first-conduction-type dopant through heat treatment, thereby forming the first-conduction-type region; wherein the formation of the capping film and the formation of the dopant layer are carried out through an in-situ process, wherein the formation of the capping film is carried out using a raw gas comprising an oxygen gas and a silicon-containing gas; and the formation of the dopant layer is carried out using the oxygen gas, the silicon-containing gas, and a dopant-containing gas containing the first-conduction-type dopant. forming the second-conduction-type region through ion implantation of the second-conduction-type dopant into the semiconductor substrate at the other surface of the semiconductor substrate; forming a capping film over the second-conduction-type region; forming the dopant layer containing the first-conduction-type dopant over the one surface of the semiconductor substrate after formation of the capping film; diffusing the first-conduction-type dopant through heat treatment, thereby forming the first-conduction-type region; wherein the formation of the capping film and the formation of the dopant layer are carried out through an in-situ process, wherein the formation of the capping film is carried out using a raw gas comprising an oxygen gas and a silicon-containing gas; and the formation of the dopant layer is carried out using the oxygen gas, the silicon-containing gas, and a dopant-containing gas containing the first-conduction-type dopant.