An image sensor that is configured to capture an image of light from a predetermined depth of a subject, the image sensor comprising: a photoelectric converter (30,104, 302) that is configured to photoelectrically convert light comprising interference light of light from the subject and reference light, and being characterized by: a discrimination unit (111, 300) that is configured to detect, by locking in, a signal component having an interference frequency in an interference light component corresponding to the predetermined depth from a signal output from the photoelectric converter (30,104, 302); and a floating diffusion unit that is configured to temporarily accumulate an electric charge resulting from the photoelectric conversion by the photoelectric converter (30, 104, 302), wherein: the discrimination unit (111,300) comprises: a transfer unit (303, 303-1, 303-2) that is configured to transfer the signal to the floating diffusion unit; a sampling unit (308,308a, 309) that is configured to sample the electric charge accumulated in the floating diffusion unit at a sampling frequency determined based on the interference frequency and; a filtering unit that is configured to separate a component having a low frequency equal to or less than a predetermined value and a direct current from a signal output from the sampling unit (308,308a, 309). a photoelectric converter (30,104, 302) that is configured to photoelectrically convert light comprising interference light of light from the subject and reference light, and being characterized by: a discrimination unit (111, 300) that is configured to detect, by locking in, a signal component having an interference frequency in an interference light component corresponding to the predetermined depth from a signal output from the photoelectric converter (30,104, 302); and a floating diffusion unit that is configured to temporarily accumulate an electric charge resulting from the photoelectric conversion by the photoelectric converter (30, 104, 302), wherein: a discrimination unit (111, 300) that is configured to detect, by locking in, a signal component having an interference frequency in an interference light component corresponding to the predetermined depth from a signal output from the photoelectric converter (30,104, 302); and a floating diffusion unit that is configured to temporarily accumulate an electric charge resulting from the photoelectric conversion by the photoelectric converter (30, 104, 302), wherein: the discrimination unit (111,300) comprises: a transfer unit (303, 303-1, 303-2) that is configured to transfer the signal to the floating diffusion unit; a sampling unit (308,308a, 309) that is configured to sample the electric charge accumulated in the floating diffusion unit at a sampling frequency determined based on the interference frequency and; a filtering unit that is configured to separate a component having a low frequency equal to or less than a predetermined value and a direct current from a signal output from the sampling unit (308,308a, 309). a transfer unit (303, 303-1, 303-2) that is configured to transfer the signal to the floating diffusion unit; a sampling unit (308,308a, 309) that is configured to sample the electric charge accumulated in the floating diffusion unit at a sampling frequency determined based on the interference frequency and; a filtering unit that is configured to separate a component having a low frequency equal to or less than a predetermined value and a direct current from a signal output from the sampling unit (308,308a, 309).