The electrochemical cell is based on a removable working microelectrode made of carbon fiber (Curr. Anal. Chem., 9, 305-311, 2013). The renewal of the surface of the working electrode is performed by electrochemical means. The carbon fiber microelectrode is suited for routine amperometric and voltammetric analyses. The device provides the user with considerable flexibility as the surface carbon microelectrodes may be suitably modified according to the required selectivity toward the substances analyzed.