An electrospray-assisted laser desorption ionization device includes: an electrospray unit including a nozzle; a voltage supplying member disposed to establish between the nozzle and a receiving unit a potential difference such that liquid drops of the electrospray medium formed at the nozzle are laden with charges, and such that the liquid drops are forced to leave the nozzle toward the receiving unit along a traveling path; a laser desorption unit adapted to irradiate a sample such that, upon irradiation, analytes contained in the sample are desorbed to fly along a flying path which intersects the traveling path so as to enable the analytes to be occluded in the liquid drops, and such that as a result of dwindling in size of the liquid drops when moving along the traveling path, charges of the liquid drops will pass on to the analytes occluded therein to form ionized analytes.