The role of the electrode material on the interfacial double layer structure of a series of ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([C₄MIM][PF₆]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₄MIM][Tf₂N]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([C₄MIM][BF₄]) was investigated on gold (Au) and platinum (Pt) electrodes. The aim of this work is to contribute with experimental data to complement theoretical models that are currently under discussion in order to describe the structure of the double layer formed at the interface electrode/ionic liquid. There is still a controversy about the general shape that differential capacitance curves should present and researchers still continue making efforts to correlate the nature of the electrode/ionic liquid with the shape of the curves. Differential capacitance curves at the Au and Pt interface shows that the values of capacity follow the same order C [C₄MIM][PF₆] < C [C₄MIM][Tf₂N] < C [C₄MIM][BF₄]. However, the values of C are considerably lower for Pt when compared with Au for all three liquids studied. The alkyl chain length effect on the differential capacity curves was also studied at the Pt/[C_nMIM][Tf₂N] interface (where n = 2, 4 and 6). The results follow an expected trend except for the liquid [C₆MIM][Tf₂N] that shows a value of capacity near to that obtained for [C₂MIM][Tf₂N]. Since ionic liquids have great applicability in energy storage devices and capacitors it is of great importance to evaluate the dependence of differential capacitance as function of temperature. The results indicate that the capacity increases with increasing temperature for all systems studied in this work.