The present invention provides an electrostatic atomizer comprising: a container having an inlet; an atomization electrode having one end projecting in the container; an opposite electrode provided in the container; a tubular collection electrode provided opposite to the atomization electrode; a mask surrounding an outer periphery of the tubular collection electrode; and a cooling part for cooling the tubular collection electrode. The opposite electrode is provided between the atomization electrode and the tubular collection electrode. The mask is formed of resin. The mask comprises a mask through-hole. The tubular collection electrode is inserted in the mask through-hole. One end of the tubular collection electrode is located in the mask through-hole. The present invention provides a method for efficiently obtaining a liquid sample from a gaseous sample and an electrostatic atomizer suitable for the method.