French judge Claude Jorda said: "There are reasons to believe that Thomas Lubanga Dyilo is legally responsible (for) ... the enrolement of children under 15.
"As a result the court confirms the charges and rules that [he] should appear before a court for trial."
Lubanga, who denies the charges, took notes and showed no emotion as the ruling was read out.
He is accused of abducting children and forcing them to participate in attacks by the armed wing of his political Union of Congolese Patriots in 2002-2003.
His lawyer has accused the prosecution of withholding information he needs to prepare the defence.
Human rights groups, however, want the charges against Lubanga to be expanded to include crimes such as killings, rape and torture.
The ICC's chief prosecutor, Luis Moreno-Ocampo, also plans to charge suspects soon for atrocities in Sudan's Darfur region, which the UN Security Council asked him to investigate in 2005.
The United States has fiercely opposed the ICC, claiming it could be used for politically-motivated prosecutions of its soldiers and citizens.