PURPOSE: To enable the shielding of the brain from an electromagnetic wave which is going to penetrate by a method wherein a cap capable of covering, at least, a head is formed of a conductor shielding member and a current collecting member is provided to a lower end of the cap.

CONSTITUTION: A cap 1 capable of covering, at least, a head is formed of a conductor shielding member 2, a current collecting member 3 is provided to a lower end of the cap 1, and, at least, one or more contact terminals 4 are provided to an adequate place of the current collecting member 3. By these processes, the head of a living body is shielded from an electromagnetic wave which is going to penetrate by wrapping it with a conductor, and a current generated in the conductor is made to be effectively discharged to another body (grounding is desirable) before a voltage is generated between the conductor and a living body or another body.