We have designed and fabricated a dual-band resonator in the terahertz frequency range on high-resistivity silicon. The device is designed to show resonances at 2.6 and $4.3\mathrm{THz}$ using the finite-difference time-domain modeling method. The characteristics of the fabricated device have been examined by using a Fourier-transform IR spectrometer. Measured results are in excellent agreement with the simulated data, showing two polarization-independent resonant peaks observed at 2.60 and $4.37\mathrm{THz}$ , respectively. The first resonance has a bandwidth of $0.56\mathrm{THz}$ , while the second one has a bandwidth of $0.70\mathrm{THz}$ . These dual-band resonant devices can be used for various applications such as dual-band spectral imaging and multiband biosensors.