JAKARTA, Indonesia — Indonesia’s top anticorruption court on Tuesday sentenced a former speaker of the country’s Parliament to 15 years in prison for embezzlement, one of the most high-profile convictions in the graft-plagued nation’s history.

The verdict against Setya Novanto, who was convicted of masterminding the theft of more than $170 million from a national identity card program, signals the downfall of one of Indonesia’s most powerful men, who had been implicated in a number of corruption scandals over the years but seemed untouchable.

“It has been convincingly proven that Setya Novanto has committed corruption together with many others,” said Judge Wanto, head of a five-judge panel at the Jakarta Corruption Court, in the Indonesian capital.

Mr. Setya, 63, sat silently and showed no emotion as the verdict and sentence were read.

When asked by the court whether he would accept the result or appeal, Mr. Setya said: “I will have to think about it.” He has a week to decide.