In Taiwan, the prosecutor, on behalf of the state, performs the power of investigation, prosecution and the execution of penalty. In criminal cases, prosecutors have the power to investigate any criminal offenses, institute or not institute prosecution, request proper application of law by courts and control and supervise the execution of judgment, and besides, as representatives of the public interest, may perform such other functions as are authorized by the Civil Code and other laws.
a.  Investigation

If a prosecutor, because of a complaint, denunciation, voluntary surrender, or another reason knows that there is suspicion of an offense having been committed, he has to immediately begin an investigation of the offender and the evidence (art. 228(1), Code of Criminal Procedure).
b.  Charging

 If evidence obtained by a prosecutor is sufficient to show that the suspect committed an offense, the prosecutor in principle has to file a prosecution with the court (art. 251(1), Code of Criminal Procedure).
c.  Trial advocacy

After initiating public prosecution, the prosecutor has to present her case at trial and express opinions after the court examines evidence. The prosecutor actively conducts witness examination at court. The system aims to help the court find the truth and achieve justice.

 If necessary, the prosecutor may express his or her opinions at trial initiated by private prosecution (art. 330(2), Code of  Criminal Procedure).
e.  Taking private prosecution

The prosecutor may take over a private prosecution in any of the following circumstances (arts. 331, 332, Code of Criminal Procedure):
‧ If a complainant, who is summoned in accordance with law, fails to appear at trial without any good reason.
‧ If a complainant appears but makes no statement.
‧ If a complainant appears but leaves without the permission of the court.
‧ If a complainant dies or loses his or her legal capacity before the closing  of argument, and no one resumes this private prosecution.
f.  Administering the execution of sentences

The proper execution of verdicts is another important part of justice. The prosecutor exercises the government's right to execute criminal penalties. Short-term incarceration sentences that may be commutable to fines are usually given lenient explanation. Installment payment terms may also be arranged for the payment of fines.
g. Other Duties

‧Protection of victims of crimes: This task includes the compensation of victims of crimes and providing assistance for them to claim  compensation.  The Reparation Review Committee for Crime Victims is organized to decide the compensation for the injured or families of victims killed.
‧Promotion of legal education: Too many people first become acquainted with the justice system as defendants. With a more fundamental knowledge of the law, and the consequences for breaking the law, more people would be equipped to make the right decisions in life. The purpose of the promotion of legal education is to help citizens understand the meanings, standards and outcomes of the law. The office does its best to help citizens fully understand their rights and obligations. The office also hopes to build public trust in the judicial system.