A subject information obtaining device according to the present disclosure includes: a first optical characteristic value distribution obtaining unit configured to obtain a first optical characteristic value distribution based on a first detection signal obtained by detecting first photoacoustic waves generated by irradiating light in a first measurement state on a subject； a second optical characteristic value distribution obtaining unit configured to obtain a second optical characteristic value distribution based on a second detection signal obtained by detecting second photoacoustic waves generated by irradiating light in a second measurement state different from the first measurement state on the subject； and a data processing unit configured to obtain a similarity distribution based on the first optical characteristic value distribution and the second optical characteristic value distribution.
