The treatment of renal and ureteral stones using a blast wave was introduced in the 1980's and after a while accepted as one of the best treatments. About 70% of the kidney stones are treated with this method. The physical mechanism for fragment stones is based on a shock wave or pulse pressure. In different models of lithotripter the pressure pulse profile is similar and only the pulse amplitude is different. A lot of research has been done to understand the mechanism of shock wave, but it can’t be said that this mechanism is fully known. The purposes of the present study were to construct components of Electrohydraulic Lithotripsy apparatus, photographing a steam bubble generated in electrode gap due to electrical disharge in water. The pressure profile resulting from the expansion of the bubble is messured by a Piezoelectric Hydrophobic Probe. Also, in experiments, the intensity of the discharge current in the electrode was measured as a function of time. The maximum pressure measured at voltage of 9 kV confirming the values reported from other experiments. Also, the degassing system designed in this project compared to the other system used for this type of equipment will reduce the concentration of oxygen to the desired level in less time. The results show that the concentration of oxygen by designed degassing method is required at 60 to 80 seconds to achive appropriate concentration level, while this time has been reported for other degassing methods one hour. Also, the diameter of the bubble was measured as a function of time. Keywords: Electrohydraulic Lithotripsy, Shock wave, Degas, Pressure measurement, Current measurement, Vapor bubble