A solar cell, comprising: a semiconductor substrate of a first conductivity type which includes a first principal surface and a second principal surface on a back side of the first principal surface; a first semiconductor layer of the first conductivity type disposed in a first region above the first principal surface or below the second principal surface; and a second semiconductor layer of a second conductivity type disposed in a second region above the first principal surface or below the second principal surface, the second conductivity type being different from the first conductivity type, the second region being different from the first region, wherein the semiconductor substrate includes: a first impurity region of the first conductivity type; a second impurity region of the first conductivity type disposed between the first impurity region and the first semiconductor layer; and a third impurity region of the first conductivity type disposed between the first impurity region and the second semiconductor layer, a concentration of an impurity of the first conductivity type in the second impurity region is higher than a concentration of an impurity of the first conductivity type in the third impurity region, the concentration of the impurity of the first conductivity type in the third impurity region is higher than a concentration of an impurity of the first conductivity type in the first impurity region, and a dose (D 2) in the second impurity region is higher than a dose (D 3) in the third impurity region. a semiconductor substrate of a first conductivity type which includes a first principal surface and a second principal surface on a back side of the first principal surface; a first semiconductor layer of the first conductivity type disposed in a first region above the first principal surface or below the second principal surface; and a second semiconductor layer of a second conductivity type disposed in a second region above the first principal surface or below the second principal surface, the second conductivity type being different from the first conductivity type, the second region being different from the first region, wherein the semiconductor substrate includes: a first impurity region of the first conductivity type; a second impurity region of the first conductivity type disposed between the first impurity region and the first semiconductor layer; and a third impurity region of the first conductivity type disposed between the first impurity region and the second semiconductor layer, a concentration of an impurity of the first conductivity type in the second impurity region is higher than a concentration of an impurity of the first conductivity type in the third impurity region, the concentration of the impurity of the first conductivity type in the third impurity region is higher than a concentration of an impurity of the first conductivity type in the first impurity region, and a dose (D 2) in the second impurity region is higher than a dose (D 3) in the third impurity region. the semiconductor substrate includes: a first impurity region of the first conductivity type; a second impurity region of the first conductivity type disposed between the first impurity region and the first semiconductor layer; and a third impurity region of the first conductivity type disposed between the first impurity region and the second semiconductor layer, a first impurity region of the first conductivity type; a second impurity region of the first conductivity type disposed between the first impurity region and the first semiconductor layer; and a third impurity region of the first conductivity type disposed between the first impurity region and the second semiconductor layer, a concentration of an impurity of the first conductivity type in the second impurity region is higher than a concentration of an impurity of the first conductivity type in the third impurity region, the concentration of the impurity of the first conductivity type in the third impurity region is higher than a concentration of an impurity of the first conductivity type in the first impurity region, and a dose (D 2) in the second impurity region is higher than a dose (D 3) in the third impurity region.