The purpose of this article is to clarify two issues related to resignation from the function performed by a member of the capital company body. The first matter is to establish a legal nature of resignation from mandate, while the other one - is the assessment of admissibility of restriction on resignation handing in to be contained in company's articles of association. By presenting the divergent judgements of the Supreme Court and the doctrine opinions, the author is expressing a view that resignation from mandate is a unilateral legal transaction. Not only a lack of prescriptive requirement for acceptance of resignation from mandate on the company side speaks for it, but also a clear reference to the regulations of civil code concerning termination of order by a contractor. Next, while clearing the matter of restriction on possibility of handing resignation in, the author is observing that membership relationship within the body may obtain a nature of better stability through specification of reasons and term of resignation. The provisions of the company articles in this field may follow two directions: firstly, the parties may restrict the admissibility of resignation making it dependent on occurrence of the specified circumstances; secondly, the company articles of association may set up a term of resignation that is a period with a lapse of which a resignation declaration becomes effective. However, considering the absolutely binding nature of Article 746 § 3 of the Civil Code, a member of the body may hand in resignation from performed function at any time by indicating important reasons, which justify his/her decision. On the other hand, if the articles set up the term of resignation, the same shall apply also to the resignation handed in for important reasons.