An optoacoustic imaging device (100) has an optoacoustic detector (20), a cross-sectional image generator (305, 306, 307, 311), and an image former (305, 306, 307, 311). The optoacoustic detector (20) has a light source (24) for irradiating a light absorber (P) inside a tested object (150) with light, and has an acoustoelectric converter (25). The acoustoelectric converter (25) detects, and generates a detection signal of, an optoacoustic wave generated by the light absorber (P). The acoustoelectric converter (25) has a plurality of detecting elements (251) arrayed one-dimensionally, and the light source (24) includes light-emitting elements (241) arranged at least between adjacent ones of the detecting elements (251). The cross-sectional image generator (305, 306, 307, 311) generates a cross-sectional image of the tested object (150) based on the detection signal, and the image former (305, 306, 307, 311) forms an optoacoustic image based on the cross-sectional image.
