The guarantee (bank guarantee) which is a new kind of ensuring implementation of obligation, established by the legislator in the new Civil Code of Ukraine has been considered in the article. The particularity of the guarantee is in its consolidation by the legislator as such kind of ensuring implementation of obligation, which has independent character, that is, does not depend on the termination or invalidity of basic obligation which is the exception among types of ensuring implementation of obligations as dependent obligations (accessory). The last one created a discussion in scientific literature on the possibility of ascribing the guarantee as unilateral transaction to the institute of types of ensuring implementation of obligation.

The author proves the position according to which understanding the essence of the independent guarantee as one of the types of ensuring implementation of obligation it is necessary to take into account the ensuring guarantee mechanism consisting of three transactions after analyzing the content of the ensuring construction of the guarantee. It is wrong to consider the guarantee only as the unilateral transaction, made by the guarantee in favor of the creditor (beneficiary) as the latter can not appear without preliminary agreement of the debtor (principal) with the guarantee on, its issuing on behalf of the creditor (beneficiary).The guarantee can not exist otherwise than a factor of ensuring construction consisting of the relations of the debtor (principal) with the creditor (beneficiary), the debtor (principal) with the guarantee, the creditor (beneficiary) with the guarantee and only in the integrity the given construction becomes itself one of the types of ensuring implementation of obligation.