再入国許可 Re-entry Permit

再入国許可とは，日本に在留する外国人が一時的に出国し再び日本に入国しようとする場合に，入国・上陸手続を簡略化するために法務大臣が出国に先立って与える許可です。
Re-entry permission is permission which is granted prior to departure by the Minister of Justice in order to simplify the immigration (entry and landing) procedures in cases where foreign nationals residing in Japan temporarily depart from Japan and intend to re-enter Japan.

日本に在留する外国人が再入国許可（みなし再入国許可を含みます。）を受けずに出国した場合には，その外国人が有していた在留資格及び在留期間は消滅してしまいますので，再び日本に入国しようとする場合には，その入国に先立って新たに査証を取得した上で，上陸申請を行い上陸審査手続を経て上陸許可を受けることとなります。
When a foreign national staying in Japan has departed from Japan without obtaining a re-entry permit (including a Special Re-entry Permit), the status of residence and period of stay permitted for the foreign national shall lapse. Therefore, if the foreign national intends to re-enter Japan, he/she needs to newly obtain a visa prior to the re-entry, file an application for landing and obtain a landing permit after going through procedures of examination for landing.

これに対し，再入国許可（みなし再入国許可を含みます。）を受けた外国人は，再入国時の上陸申請に当たり，通常必要とされる査証が免除されます。また，上陸後は従前の在留資格及び在留期間が継続しているものとみなされます。
In the meantime, a foreign national who has obtained a re-entry permit (including a Special Re-entry Permit) is exempted from presenting a visa, which is ordinarily required, upon filing an application for landing at the time of re-entry. Furthermore, after landing in Japan, his/her previous status of residence and period of stay are deemed to remain valid.

再入国許可には，１回限り有効のものと有効期間内であれば何回も使用できる数次有効のものの２種類があり，その有効期間は，現に有する在留期間の範囲内で，５年間（特別永住者の方は６年間）を最長として決定されます。
There are two types of re-entry permit: a permit that is valid only once and a multiple re-entry permit that can be used multiple times until the expiration date. The period of validity for re-entry permit shall be determined within the current permitted period of stay for up to five years (or six years for special permanent residents).