A drowsiness estimation device comprises an imaging unit 1, a regional temperature calculation unit 6, and a weighted subtraction unit 7. The imaging unit 1 obtains visible spectrum image data in a visible spectrum capture mode and obtains infra-red image data indicating a surface body temperature distribution for a subjects body in an infra-red capture mode. The regional temperature calculation unit 6 detects a temperature of an ocular center region within the surface body temperature distribution indicated by the infra-red image data. The weighted subtraction unit 7 applies a correction to a temperature parameter for drowsiness estimation, based on the detected ocular center region temperature. A drowsiness estimation for the user is then performed according to the corrected parameter.