The microwave power deposition profiles near the first (ω = 28 GHz) and the second (ω = 56 GHz) harmonic, for the magnetic configuration of the flexible heliac TJ-II, using several plasma density and temperature profiles, are obtained. Relativistic corrections to the dielectric tensor in the first harmonic are introduced, and a shift of the cyclotron resonance frequency into the region of higher magnetic field is found. Absorption considerations show that ECRH is not only a suitable way of plasma heating in this device but can, in addition, be used to control the temperature profile in the plasma.