JERUSALEM — A Palestinian woman who spent more than 40 days on a hunger strike to protest her detention by Israel without charge or trial was released from an Israeli prison on Sunday and sent into temporary exile in Gaza under a deal reached with the Israeli authorities.

The woman, Hana Shalabi, 30, from the northern West Bank, was the second Palestinian this year to have challenged and changed the terms of their “administrative detention,” a practice of the Israeli military courts that allows imprisonment based on secret informants or information and that has been used against thousands of Palestinians over the years.

Both Ms. Shalabi’s case and that of Khader Adnan, 33, who ended a 66-day fast in February in return for a reduced term, drew international attention to the continuing use of administrative detention and prompted concerns in Israel that a hunger strike to the death could set off widespread unrest.

But both cases were resolved individually and have so far failed to produce any fundamental change in Israeli policy.

Ms. Shalabi had previously spent more than two years in administrative detention before being released in October 2011 as one of hundreds of Palestinian prisoners exchanged for Gilad Shalit, an Israeli soldier who had been held in Gaza. She was rearrested in February and handed a six-month detention order that was later reduced to four months.

The Israeli military said in a statement that she was originally placed in detention in 2009 on the basis of information that she intended to carry out a suicide attack against Israelis, and that intelligence reports had indicated that she had recently “resumed terrorist activity.”

Ms. Shalabi’s brother, Omar Shalabi, 42, rejected those accusations. “If they were true, she would have been sentenced,” he said in a telephone interview shortly before Ms. Shalabi’s deal with the authorities was made public toward the end of last week.

Israel defends its use of administrative detention as necessary for national security, and says it is used when a case is based on informants or intelligence material that cannot be revealed in court. Critics say the secret evidence makes it impossible for administrative detainees or their lawyers to mount a proper defense. Administrative detention orders can be issued for a maximum of six months, but can be renewed indefinitely. About 300 administrative detainees are currently in Israeli prisons, officials say.

Mr. Adnan was said to have been a leader of Islamic Jihad, an extremist organization that has carried out suicide bombings and fired rockets from Gaza into southern Israel.

Ms. Shalabi is also said to belong to Islamic Jihad. When she entered Gaza on Sunday, supporters and leaders of the movement were waiting for her at the Erez crossing. Islamic Jihad did not welcome the deal made with the Israeli authorities, which will confine Ms. Shalabi to Gaza for three years, but said that it respected her decision.

“Shalabi won over the Israeli occupation, and she is coming to a part of her homeland, Gaza,” Khaled al-Batsh, an Islamic Jihad leader, told reporters near Erez. “She will go back to her family and hometown in the West Bank someday.”

A Palestinian ambulance picked up Ms. Shalabi at the crossing point and sped her to Al-Shifa hospital in downtown Gaza, passing about 100 Palestinians who had gathered to greet her, holding Palestinian flags and her portrait.

Several other Palestinian prisoners are now on hunger strike to protest the terms of their imprisonment. According to Qadura Fares, the president of the nongovernmental Palestinian Prisoners Society based in Ramallah, the West Bank, two of them have been taking only water and salt for more than a month.