TOKYO — A Tokyo court handed down a two-and-a-half-year prison sentence on Friday to the former head of Mt. Gox, a cryptocurrency exchange that helped establish Bitcoin as a household name before spectacularly imploding amid allegations of mismanagement.

Still, Mark Karpelès, the French national who presided over Mt. Gox’s rise to become the world’s largest Bitcoin exchange, will not serve additional time if he remains on good behavior.

The verdict ended a more-than-five-year ordeal for Mr. Karpelès, who was found guilty on a charge of falsifying data but innocent of two additional charges of embezzlement and breach of trust. He was arrested in August 2015 and held for almost a year in detention, where he spent months under interrogation by prosecutors who upped the pressure by adding more charges against him.

His sentence was suspended for four years, effectively meaning he will serve no additional jail time as long as he remains on good behavior.