The objective of this research was to carry out the microwave and hydrothermal reduction of graphene oxide (GO) and to examine the capacitive properties of prepared samples (rGO1, rGO2 and rGO3). Olive leaf extract (ELM) was used as a reducing agent. The GO reduction process in the microwave reactor was carried out for 5 minutes at a temperature of 120 °C. The reaction was performed at pH values 7 (rGO1) and 8 (rGO2). The rGO sample rGO1 was applied to a piece of carbon cloth while the rGO2 sample was applied to the glassy carbon support. The reduction process in the hydrothermal reactor took six hours; 1 h at temperature of 50 °C, then 5 h at temperature of 180 °C. The GO reduction to rGO3 was carried out at pH 3 and it resulted in graphene hydrogel formation. One part of obtained rGO hydrogel was directly was used to assemble supercapacitor while the other part was dried, dissolved in Nmethyl- pyrrolidone (NMP) and afterwards it was applied to the glassy carbon support in order to perform electrochemical examinations. The successful performance of the process was proved by FT-IR spectroscopy and cyclic voltammetry method. Cycliclic voltammetry was carried out in 0.5 mol dm^-3 Na2SO4 solution. The obtained specific capacitance of electrodes containing the sample prepared by microwave synthesis and subsequent drying ranged from 3.00-306.26 F g^-1, while the sample value prepared by hydrothermal synthesis was 18.57 F g^-1. It has been shown that specific capacitance values depend to a large extent on the amount of sample being applied. Namely, by increasing the mass of the sample applied to the support, the value of the specific capacitance is reduced. In addition, the purpose of this paper was to examine the capacitive properties of supercapacitor assembled by using rGO3 hydrogel as active material. Prepared supercapacitor was tested by cyclic voltammetry method in two-electrode system. As a result, the obtained specific capacitance of supercapacitor was 34.55 F g^-1. The obtained value indicates that the specific capacitance is higher for hydrogel directly used compared to the hydrogel treated by the additional drying steps. The shape of cyclic voltammogram indicates good capacitive behaviour of supercapacitor.