There is an increasing demand of certified and efficient ethical hackers to combat the rising challenges in the field of cyber security.

Any individual to become an Ethical Hacker should possess the most important requisite know-how of computer networking with a minimal hands-on experience that will be helpful.
You may also learn some programming language - be it Java, C, C++, LISP or Perl etc.

An individual needs to take proper training and certification for Ethical Hacking, i.e. the CEH Course offered by EC-Council.

Otherwise there is as such no other qualification mandate to become an ethical hacker.
Good luck.