arranged so as to allow the user to set multiple ranges of colors or luminous intensity values such as concurrently selecting both red and violet regions or two brightness levels ranging 0 black 0 2 and 0 8 1 white for example after determining that the selected region is appropriate the user operates the input device 22 to effect the command to begin the analysis the scanning controller 204 transmits a control signal to the stage actuator 14 to move the sample stage 16 to position an edge dot a in fig5 of the selected region to the laser beam irradiation location when the dot a reaches that location the scanning controller 204 sends a command to the stage actuator 14 to allow for the scanning of the region with a laser beam spot in response to the command the stage actuator 14 operates the sample stage 16 to repeat the following move the sample stage in the direction x by a short predetermined distance u03b4x and pause for a short predetermined duration at each location fig5 the laser controller 205 transmits a command signal to the laser irradiating system 13 to emit a laser beam to that location while the sample 12 is at a stop this generates ions from the sample and the ions generated.