Here it is from the source

1. Be interested in Japan, and be willing to deepen their knowledge of Japan and participate in international exchange activities within the community after their arrival.

2. Be both mentally and physically healthy.

3. Have the ability to adapt to life and work in Japan.

4. Obey all Japanese laws.

5. Applicants with a suspended jail term must have finished their period of probation by the time they submit their application form.

6. Be a citizen (not just a permanent resident) of the country where the recruitment and selection procedures take place. (Those who possess dual citizenship with Japan must renounce their Japanese citizenship before the date for submission of the JET Programme Reply Form.) Applicants who have dual citizenship with countries other than Japan may only apply in ONE country.

7. In principle, be forty (40) years of age or less (as of April 1st, 2010). One of the main purposes of the Programme is to foster exchange between Japanese youth and young professionals from the countries participating in the Programme.

8. Have excellent pronunciation, rhythm, intonation and voice projection skills in the designated language (See Note 1), in addition to other standard language skills. Have good writing skills and grammar usage.

9. Not have participated on the JET Programme since 2007. Also, not have been a participant on the Programme for more than a total of five years (See Note 2).

10. Not have declined a position on the JET Programme after receiving notification of placement in the last JET Programme year. However, exceptions to this rule may be made in cases where it is determined that the participant has a valid, unavoidable reason for withdrawing.

11. Not have lived in Japan for six or more years in total since 2000 (See Note 2).

12. In the case of entry into Japan for the participation in the JET Programme, agree to reside in Japan under the status of residence stipulated in Article 2-2 of the Immigration Control and Refugee Recognition Act.

13. Be interested in the Japanese educational system and particularly in the Japanese way of teaching foreign languages.

14. Be interested in actively working with students.

15. Hold at least a Bachelor?s degree or obtain one by the departure date of Group A participants (See Note 3), or hold a qualification of three years of more in a training course in teaching at elementary or secondary schools or be able to obtain such qualifications by the departure date of Group A participants.

16. Be qualified as a language teacher or be strongly motivated to take part in the teaching of foreign languages (See Note 1).

17. Successful applicants are expected to make an effort to study or continue studying the Japanese language prior to and after arriving in Japan.

18. In addition to the above, applicants from non-English speaking countries must:
Have a functional command of the English or Japanese language.