The court of first instance is the court which in the course of the session explores the evidence establishes the facts and circumstances of the case, issue a decision. In criminal proceedings at first instance examines the case for conviction or acquittal of the defendant. In civil and arbitration proceedings to decide issues of satisfaction or denial of the claim, its proof or lack of proof.

In the first instance may be any court, including the highest levels of the judicial system, with the exception of the Arbitration courts of appeal and the Federal arbitration courts of districts. Most civil and criminal cases investigated in the first instance of the city and district courts, justices of the peace, and in the arbitration process – the arbitration courts of the Russian Federation. The most complicated cases are heard on the merits in the Supreme courts of subjects of Federation (republics, territories, regions, etc.), and special can get into the production of the Supreme Court.

Criminal cases can deal in first instance in 3 options of the justices:
one judge (Federal or world);
- one judge and 12 jurors;
- 3 Federal judges.
Research evidence and decision-making in most cases by a single judge, but at the request of the defendant the court of first instance can be formed in a collegial form.

When considering civil cases in first instance, the court is obliged to hear the explanations of the parties and other persons participating in business, indications of witnesses, expert witnesses, examine written and physical evidence. In criminal procedure in first instance is the interrogation of the accused, victims, witnesses and other participants in the process, is the examination of material and study of written evidence, etc. In the arbitration process, the court examines the economic merits of the dispute or an unlawful act of state authorities, considers the written evidence and shall hear arguments of the parties.

Following the consideration of the court of first instance in civil and arbitration matters, the decision, and in criminal – sentence. In the process, the court may issue rulings and orders. All decisions of the court of first instance can be appealed in cassation or appeal to a higher court.