The book of Īśā Upaniṣad is upanisad which is quite unique and important. Īśā upaniṣad is the shortest and smallest upaniṣad of all 18 types of upaniṣad, but is the most important upaniṣad of all upaniṣad books in Hinduism. Īśā Upaniṣad is always associated with Veda Śruti, the Yajur Veda Putih (Śukla Yajur Veda). Īśā Upaniṣad is in addition to the notion of Īśā, as well as some of the teachings on which Hinduism is based.The results of this study can be described that the principles of the teachings contained in Īśā Upaniṣad, namely divinity, karma, the universe, vidyā and avidyā. God is called Īśā. The absolute Iśā, and the Impersonal. The universe and all its contents are either soul or soulless, controlled by Īśā. Therefore every living creature fights steadily with the karma and closer to God in his life. Furthermore, Hindu theological teachings contained in Iśā Upaniṣad, namely: God almighty, God can not be thought, God is the source of all, God is everywhere, ātman, sambhūti and asambhūti. God is called Īśā, essentially Esa, the source of everything that exists in the universe and becomes the place of the return of all things. The one, while still in place, does not move, but his speed exceeds the mind, preceding the velocity of the Gods. God is unthinkable, supernatural, pervading everything, everywhere.