The bomb maker, a man named Ibad, was given a five–year sentence. Ibad told the court that he received funding and guidance for the attack from Bahrum Naim, a radical Islamist linked to the January suicide attacks in Jakarta that killed eight people.
Ibad's lawyer said his client and Naim had known each other for many years before Naim travelled to Syria to become an element in IS’ so-called holy war.
He said Ibad had been coerced by Naim through social media to carry out an attack in Solo city on Java island.
Three other defendants were also found guilty of the failed bomb plot and given sentences of four years and eight months.
Police believe hundreds of Indonesians have travelled to Syria to join militant groups including IS.