Of the 47 members of the Council, 24 voted in favor of the resolution, 9 voted against and 14 abstained.
The United States regrets the decision and believes it could disrupt "recent progress".
The Israeli Foreign Ministry declares that the country will not cooperate with the investigation, and labels it as an attempt to "excuse crimes committed by the terrorist organization Hamas".
Air raids can be war crimes
UN High Commissioner for Human Rights Michelle Bachelet said during a special session of the UNHRC that Israel's deadly airstrikes against Gaza could constitute war crimes if they prove to be disproportionate.
Bachelet further said she had not seen any evidence that civilian buildings affected by the airstrikes in Gaza were being used for military purposes.
"If they turn out to be disproportionate, those types of attacks can be war crimes," she said.
Urged Hamas
The head of human rights also called on Hamas, the terrorist movement that controls Gaza, to refrain from firing rockets at Israel indiscriminately.
A ceasefire last week put an end to eleven days of flare-ups between Israel and Hamas.
According to official figures, more than 250 people were killed on the Palestinian side and 12 in Israel.