An access control method of a semiconductor device includes providing an inputted password as an input of a hash operator; performing a hash operation in the hash operator and outputting a first hash value; controlling the hash operator so that the hash operation is repeatedly performed in the hash operator by providing the first hash value as an input of the hash operator when the first hash value and a second hash value stored in a nonvolatile memory do not coincide; and setting an access level with respect to the inner circuit according to the repetition number of times of the hash operation of the hash operator when the first and second hash values coincide.