[en] High-purity germanium (HPGe) detectors are widely used to determine quantitatively the concentrations of natural and artificial radionuclides in environmental samples. Even with detectors of high performance, it is difficult to measure environmental samples with small activity concentrations. In the case of low-level radioenvironmental measurements at close geometry, much care has to be dedicated to the efficiency calibration of the spectrometer used. This is because the full-energy-peak efficiency is a complicated function of many parameters, such as the energy of gamma-ray, the dimension of the detector, the dimensions of the source, the geometrical arrangement of the detector and source, and the density of the sample. In the present work, the relative efficiency curves for the 10% p-type HPGe detector for environmental samples placed in a cylindrical container were constructed using ⁶⁰Co, ¹³³Ba and ¹⁸²Ta solutions. (author)