An electrostatic probe for ion temperature and density measurements was built and tested in the scrape‐off region of the TBR‐1 small tokamak. The main parameters involved in the design and details of the construction of the probe are presented. The electron discrimination and the probe efficiency for ion detection were checked by measuring the probe current as a function of the collector retraction length for a constant voltage. The results for the ion temperature and density obtained from the characteristic curves are discussed and compared with previous measurements.