An optoacoustic imaging device has an optoacoustic wave detector, a cross-sectional image generator, and an image former. The optoacoustic wave detector has a light source for irradiating a light absorber inside a tested object with light, and has an acoustoelectric converter. The acoustoelectric converter detects, and generates a detection signal of, an optoacoustic wave generated by the light absorber. The acoustoelectric converter has a plurality of detecting elements arrayed one-dimensionally, and the light source includes light-emitting elements arranged at least between adjacent ones of the detecting elements. The cross-sectional image generator generates a cross-sectional image of the tested object based on the detection signal, and the image former forms an optoacoustic image based on the cross-sectional image.
