Ban said too many people had died and there had been too much civilian suffering.
"My message is simple, direct and to the point: the fighting must stop," Ban told a news conference in New York ahead of his departure on Tuesday for the Middle East.
"In Gaza, the very foundation of society is being destroyed: people's homes, civic infrastructure, public health facilities and schools."
His diplomatic tour will see talks with the leaders of Egypt, Israel and Syria as well as the Palestine Authority chief in Ramallah.
It is not clear whether he will go to Gaza itself during his week-long trip.
Palestinian medical sources say 910 people have been killed in Gaza so far, of whom 292 were children and 75 were women.
Israel says 13 Israelis, including three civilians, have been killed.