The living body state estimation device 1 comprises: a physiological information detection unit 2 having a physiological information feature amount calculation unit 22 that calculates physiological information feature amounts on the basis of physiological information of a driver 11 acquired by sensors 21 a facial expression detection unit 3 having a facial expression feature amount calculation unit 32 that calculates facial expression feature amounts on the basis of facial expression information extracted from images of the drivers 11 face captured by a camera 31 a state estimation unit 4 that estimates the state of the driver 11 on the basis of the physiological information feature amounts and the facial expression feature amounts and a physical stimulus generation unit 5 that generates a physical stimulus to be provided to the driver 11. The state estimation unit 4 acquires changes in physiological information feature amounts and changes in facial expression feature amounts before and after a physical stimulus generated by the physical stimulus generation unit 5 is provided, and based on said changes, carries out weighting of the physiological information feature amounts and the facial expression feature amounts when estimating the state of the driver 11.Cette invention concerne un dispositif destimation détat dun corps vivant comprenant : une unité de détection dinformations physiologiques 2 comportant une unité de calcul de quantité de caractéristiques dinformations physiologiques qui calcule des quantités de caractéristiques dinformations physiologiques en fonction des informations physiologiques dun conducteur acquises par des capteurs une unité de détection dexpression faciale 3 comportant une unité de calcul de quantité de caractéristiques dexpression faciale 32 qui calcule des quantités de caractéristiques dexpression faciale en fonction des informations dexpression faciale extraites dimages du visage du conducteur 11 capturées par une caméra 31 une unité
