Operation of a sensor node of a wireless sensor network with energy har- vesting is described by the single-server queue. Customers and energy units arrive according to the marked Markov arrival process. Service of a customer is possible only in presence of an energy unit. We assume that, besides the use of one energy unit for service of any customer, one more unit is expended at the moment of a customer arrival if the customer is accepted to the system. To optimize operation of the system, a parametric strategy of admission control is used. Under the ﬁxed value of control parameter, the behavior of the sys- tem is described by the ﬁve-dimensional Markov chain. The generator of this Markov chain is obtained. Expressions for computation of the key performance indicators of the system are presented.