It is well known that water-based commercial explosives locally ignited in closed vessels do not undergo self-sustained combustion when the pressure is lower than some threshold value. The latter is usually referred to as the Minimum Burning Pressure (MBP) of the explosive and is now being used by some manufacturers as a basis of safety for many associated manufacture, transport, and handling processes. In the present work, both an apparatus based on hot-wire ignition and an associated methodology were developed to measure the MBP of water-based explosives. Typical results for various emulsion and water-gel explosives are also reported and discussed. It is also shown that the technique could be used to characterize very insensitive explosive substances normally used as explosive precursors.