This course is introductory solid state physics for seniors of the physical sciences. In the years since the first lecture was presented the field has developed vigorously, and there are notable applications. The challenge to the lecture has been to treat significant new areas while maintaining the tntroductory level of the lecture. It would be a lucky to present such a physical field as a homework. In this semester we will study five topics which include energy band, seimconductor, metal, superconductor, and magnetism. In the first half of the semester most of lecture will be focused on basic concept of energy band based on quantum physics. In the second half of the semester we will focus on semiconductor and various materials by employing quantum mechanics. The subjects which have been treated in this semester will be applied to diverse new materials.