An optical pickup, an inclination angle detection method, an optical information device, and an information processing device capable of reliably and accurately detecting a relative inclination angle between an end face of a solid immersion lens and a surface of an optical recording medium are provided. A convergence position modifying unit modifies convergence states of a first beam and a second beam according to layers of an optical recording medium, a first optical detector includes a first light receiving section which receives the converged first beam and a second light receiving section which receives the converged second beam, and the first optical detector detects a relative inclination angle between an end face of a solid immersion lens and a surface of the optical recording medium based on a difference in quantities of received light between the first light receiving section and the second light receiving section.