The purpose of the thesis is to examine the liability of an arbitrator for damages caused to the parties of arbitration in cases where the arbitration proceedings are based on an agreement between the parties and are carried out under the Finnish Arbitration Act. The study follows a juridical research method and the source material of the study consists mainly of juridical literature.

The relationship between an arbitrator and the parties of arbitration can be un-derstood as a contractual relationship, which makes it possible to apply to it the principles of contractual liability. The liability of an arbitrator seems to be possible – even if rare in practice – in case the arbitrator delays the arbitration proceedings, the arbitrator abandons his/her role without presenting an acceptable reason, or due to the nullity or relative nullity of the arbitration award. The liability seems to be clearer in the cases where an arbitrator violates his/her obligation in a situation where no judicial consideration has been required. Situational factors do affect to the consideration of the liability of an arbitrator and the ambiguousness of the arbitration obligation can preclude the liability. The liability of an arbitrator due to violating confidentiality is partly unclear due to a weak normative basis of confidentiality. The rise of a liability due to inaccuracy of an arbitration award relating to substantive law appears to be very unlikely.