A biological subject transfer device comprising an image capturing system comprising: an image capturing device capable of performing first image capturing to capture an image of a biological subject accommodated in a first container and second image capturing to capture an image of the biological subject after predetermined work is performed, the predetermined work being work of transferring by the biological subject transfer device the biological subject selected as a transfer target from the first container accommodating a plurality of biological subjects to a second container; a storage unit configured to store data regarding the selection criterion; a head device configured to perform transfer work of picking the biological subject selected as the transfer target from the first container accommodating the plurality of biological subjects and transferring the biological subject to the second container as the predetermined work; a determination unit configured to make a first determination to determine whether to select the biological subject based on a predetermined selection criterion from the image acquired by the first image capturing, characterized in that the determination unit is additionally configured to make a second determination to determine whether to select the biological subject from the image acquired by the second image capturing; a correction unit is configured to update the selection criterion data stored in the storage unit such that the first determination and the second determination about the biological subject become identical in a subsequent determination when the first determination and the second determination have different determination results; and the predetermined work further includes work of waiting for an elapse of a predetermined test time after having transferred the biological subject to the second container before the second image capturing is performed by a camera unit after the first image capturing. an image capturing device capable of performing first image capturing to capture an image of a biological subject accommodated in a first container and second image capturing to capture an image of the biological subject after predetermined work is performed, the predetermined work being work of transferring by the biological subject transfer device the biological subject selected as a transfer target from the first container accommodating a plurality of biological subjects to a second container; a storage unit configured to store data regarding the selection criterion; a head device configured to perform transfer work of picking the biological subject selected as the transfer target from the first container accommodating the plurality of biological subjects and transferring the biological subject to the second container as the predetermined work; a determination unit configured to make a first determination to determine whether to select the biological subject based on a predetermined selection criterion from the image acquired by the first image capturing, characterized in that the determination unit is additionally configured to make a second determination to determine whether to select the biological subject from the image acquired by the second image capturing; a correction unit is configured to update the selection criterion data stored in the storage unit such that the first determination and the second determination about the biological subject become identical in a subsequent determination when the first determination and the second determination have different determination results; and the predetermined work further includes work of waiting for an elapse of a predetermined test time after having transferred the biological subject to the second container before the second image capturing is performed by a camera unit after the first image capturing.