A MALDI ion source includes a sample plate for receiving a sample, a laser for producing laser radiation to ionize the sample, a first optical element arranged so as to direct the laser radiation along a first optical path toward the target area, and a second optical element arranged along the first optical path to focus the laser radiation onto the target area. The first and second optical elements are arranged that light that is reflected from the target area travels along the first optical path through the first and second optical elements, the first optical element reflecting the laser radiation along a first direction and transmitting the light reflected from the target area that has traversed the first optical path in a second direction. An imaging device for viewing the plate surface may be arranged to receive the light that has been reflected from the target area and has traversed the first optical path through the first and second optical elements.