A thermoacoustic refrigerator working with nitrogen gas is investigated near the resonance condition. The gas oscillations with frequencies varying from 5 to 80 Hz are produced by a mechanical driver mounted at one end of the resonant tube containing the heat exchangers (cold and hot) and the regenerator (parallel stack of plates). Detailed experimental data of oscillating pressure amplitude and phase shift at two locations of the resonant tube are given as a function of the driving frequency for a fixed gas mean pressure. These results, compared with the analytical prediction derived from the network theory, show a good agreement. Once the acoustical properties (acoustic pressure and velocity) have been determined, the energy flow (heat and work) is then calculated along the resonant tube and the heat flux pumped at the cold end of the stack, Qc, is deduced as function of the working frequency for various temperature differences between heat exchangers, ΔT. These calculations show a good agreement with the experimental results which put forward a maximum heat pumping close to the resonance condition.