A people counting device includes: a person presence region extraction unit which extracts a region in which a person is present by performing person detection in relation to an input image; a person presence state estimation unit which estimates a person presence state from an extraction result; a portion detector selection unit which selects a type of portion detector to be used for people count measurement based on the estimation result, and outputs portion detector information. The people counting device further includes: a portion detection process unit which performs a portion detection process for detecting a portion of a person based on the portion detector information; and a people counting unit which obtains a number of people within the input image from a portion detection process result.