A solid-state image sensor for automatic focus with highly precise automatic focus performance is realized at low cost. In the solid-state image sensor for automatic focus which has paired linear sensors (L1 to L10) respectively provided with linear sensors for standard portion (L1-B to L10-B) and linear sensors for reference portion (L1-R to L10-R) for performing phase difference detection type focus detection, a linear sensor for standard portion L6-B of paired linear sensors L6 is arranged between a linear sensor for standard portion L5-B and a linear sensor for reference portion L5-R of paired linear sensors L5, and a linear sensor for reference portion L5-R of paired linear sensors L5 is arranged between a linear sensor for standard portion L6-B and a linear sensor for reference portion L6-R of paired linear sensors L6.