Kommentar Deutsches Bürgerliches Gesetzbuch:
Ein Ehefähigkeitszeugnis benötigen nach § 1309 Abs. 1 des deutschen Bürgerlichen Gesetzbuchs (BGB) Ausländer, die in Deutschland eine Ehe eingehen wollen, wenn sie hinsichtlich der Voraussetzungen für die Eheschließung ausländischem Recht unterliegen. Nach Art. 13 des Einführungsgesetzes zum Bürgerlichen Gesetzbuch (EGBGB) richten sich für jeden Verlobten die Voraussetzungen der Eheschließung nach dem Recht des Staates, dem er angehört. 国際結婚手続き用語集：
婚姻要件具備証明書
婚姻具備証明書とも言います。
簡単にいうと、結婚できる条件があるかどうか、証明する書類。つまり、この人は、他の人と結婚していないことを証明するもののようです。 英語では、Affidavit of Competency to MarryあるいはCertificate Of No Impedimentといいます。 外国人配偶者が提出を必要とされる書類で、在日の各国大使館あるいは、本国で申請して取得するようですが､国によってはこの証明書そのものを発行していないところもあります。その場合は、宣誓書、申述書などで代用するようです。 Australian Government, Department of Foreign Affairs and Trade:
Certificates of No Impediment to Marriage are issued by the Department of Foreign Affairs and Trade through overseas missions and state and territory offices to Australian citizens seeking to marry overseas. Certificates of No Impediment to Marriage are not a requirement of Australian law. They are issued purely at the request of overseas countries seeking to ensure that a marriage involving one or two Australian citizens, celebrated in that overseas country, will also be recognised as a valid marriage by Australian authorities. In Australia, application forms for the Certificate of No Impediment to Marriage (pdf) are available from any state or territory office of the Department of Foreign Affairs and Trade.
Some countries will only accept Certificates of No Impediment issued by the local Australian Embassy or Consulate in the country in which the marriage is to take place. However, if authorities of the country in which the marriage is to take place have advised that they will accept a Certificate of No Impediment issued in Australia, you should complete the application form for a Certificate of No Impediment to Marriage and return it to your state or territory office of the Department of Foreign Affairs and Trade. The Consular Fee for a Certificate of No Impediment to Marriage is $90.
In addition to the Certificate of No Impediment to Marriage, the Department of Foreign Affairs and Trade can provide general advice on the requirements which may need to be met in order for a marriage to be legal in a particular country. For exact details of what requirements will need to be met, persons wishing to marry overseas should contact the embassy or consulate of the country in which they would like to marry. The following general information may be of assistance.
Overseas marriage authorities often require evidence that the party is free to marry. Such evidence may be a statement from the Registry of Births, Deaths and Marriages that there is no record of the person having been previously married. Authorities may also require divorce papers/death certificate of a former spouse in the case of being divorced or widowed. Overseas marriage authorities generally will also want to sight an original birth certificate and the person’s passport. Foreign marriage authorities may have further additional requirements e.g. a requirement to reside for a length of time in a country prior to a marriage taking place in that country. | 
