The effect of the laser energy on the ion signal intensity was studied with the use of a quadrupole-based laser ionization mass spectrometer by varying the laser pulse energy over a range of 2 to 24 mJ. The experiment showed increase of the ion signal intensity with the laser energy up to the peak at 8 mJ. Reconstruction of the ion chamber to introduce retarding electric field in it was found to be more effective to increase the ion signal intensity and signal to noise ratio.