The accident at Freeport-McMoRan's Grasberg mine, high in the mountains of Papua province, happened in a mining area, said Riza Pratama, spokesman for the company's Indonesia unit.
The victim suffered severe injuries and died on the spot, he added. The spokesman did not give further details but Tempo news website reported that the employee died after falling onto a conveyor belt.
Grasberg, one of the world's biggest gold and copper mines, has been plagued by accidents and production problems in recent years.
In January, three security personnel who had been patrolling the mine were found dead with bullet and machete wounds, AFP reported.
In May 2013, a training tunnel collapsed, killing 28 miners as they took part in a safety course, in one of Indonesia's worst-ever mining accidents.