A Vatican spokesperson said: “Last night the Pope Emeritus was able to rest well. He also participated in the celebration of Holy Mass in his room yesterday afternoon.
“At present his condition is stable”.
Pope Francis warned on Wednesday that his 95-year-old predecessor was seriously ill and urged everyone to pray for him.
The Vatican said on Thursday that the former Pope “was able to rest well last night”.
Benedict XVI became the first leader of the Catholic Church to stand down in 600 years in 2013. He said his advancing years meant he could no longer continue in the role.
When he was elected Pope in 2005 at the age of 78 he had earned a reputation as a conservative enforcer of Church doctrine.
Born Joseph Ratzinger, he was the first German Pope for 1,000 years, but his health was already in decline and within eight years he decided to step down.
Pope Francis did not reveal the specifics of the illness affecting Benedict, but said: “I would like to ask for a special prayer for Pope Emeritus Benedict, who in silence is supporting the church.
“I remind you that he is very sick. Let’s ask the Lord to comfort him and support him in this testimony of love for the church until the end.”