In many complex flow fields, such as those encountered in combustion chambers, swirl atomizers, gas separators, and turbomachines, the mean-flow direction is not well known. However, quite often the experimental determination of the three-dimensional, steady-state characteristics of these flows is required. One of the most suitable instruments for measuring mean-flow values in such situations is the directional pressure probe. Presented in this paper are the results of a program to construct, calibrate, and employ a special type of directional pressure probe which is called: five-tube pressure probe or 5TPP. Topics such as calibration techniques, various sources of errors, and correction procedures are discussed in detail. Preliminary tests, which included measurements in the initial region of a turbulent jet in a coflowing stream, have shown fair agreement between the measurements of velocity with a 5TPP and with a standard hot-wire probe.