Abstract: The excimer lasers are novel laser source for industry procedure.In order to obtain the optimum process parameters for various processing condition,we have to now the laser beam quality characteristic, such as energy stability of laser pulses sequences,laser pulse duration and its stability,beam divergence and its stability and energy distribution on spot,except for operating wavelength,maximum pulse energy,pulse repetition and average power.So we used a set of dignotic techniques to evaluate the beam quality of Lambda Physik LPX 305iF KrF laser for excimer laser micro-machining.