Microwave thermal ablation is under investigation for minimally invasive treatments. In the cases of small targets, such as adrenal glands, microwave thermal ablation is a valuable alternative to the traditional and more invasive treatments (e.g. surgical procedures, pharmaceutical therapies). In this work, ablation treatments are carried out on ex-vivo liver samples using a custom developed microwave ablation applicator for ablation of small targets. Ablation zones achieved with different treatment settings are analysed. The power and time settings suitable to achieve a small and well controlled ablation zone, are evaluated. Moreover, the temperature increase in different regions of the area under treatment is assessed.