STIM tomography has been recently implemented in the nuclear microbeam line of the CENBG. In addition to the design of the experimental device, the main development consisted in the elaboration of data reduction programs based on analytic reconstruction methods usually employed for X-ray tomography. This report describes the first results that we obtained in the analysis of biological samples. In a first step, plant specimens such as single pollen grains and stamens were investigated in order to assess the performances of the technique. Individual cells isolated from a human cancer cell line were then analysed. One of the main advantages pointed out by these experiments is the capability to reveal the cell ultrastructure using simply freeze-dried unsectioned specimens.