Answer in Details
For example, the Kashmir Shaivism tradition teaches that the innermost Self (Atman) is none other than Paramashiva, the absolute, all-pervading consciousness. The realization that "I am Shiva" (Shivoham) is considered the highest spiritual attainment.
Although the term "Brahman" is more frequently used in Advaita Vedanta to denote the ultimate reality, in Shaiva texts, Shiva fulfills the same role—the transcendental, formless, infinite consciousness. Many Shiva devotees and scriptures declare, "Shiva is the Atman, the Self of all."
So, within the teachings of Lord Shiva, the inner self is Shiva—the highest, pure consciousness residing within every being.