High voltage (HV) impulse generators are employed widely for testing of HV apparatus, as such tests are codified in a range of standards. As a result, insulation properties under impulse waveforms are of interest in the design of HV apparatus. This creates a need for very low energy laboratory impulse generators which can be used to test laboratory scale samples, often in conjunction with sensitive electronic instrumentation to measure sample dielectric properties. Since the sample is often the only isolation between the impulse generator and the electronics, failure of the sample will result in exposure of the electronics to the energy stored in the generator. This paper provides design details for a very low energy (/spl sim/1 nF storage), single-stage impulse generator which provides clean double exponential waveforms.