A droplet-ejection detecting device for detecting ejection of droplets from a plurality of nozzle orifices, includes: a beam scanning mechanism which scans a plurality of droplet ejection lines along which droplets ejected from the nozzle orifices fly, by emitting a beam to intersect the droplet ejection lines, thereby subjecting the droplets to irradiation with the beam; a light receiving unit which receives light obtained as a result of the irradiation; and an ejection determining mechanism which determines safe ejections of the droplets from the nozzle orifices based on a received-light signal output from the light receiving unit.