A surveillance device comprising: a surveillance logic receiving unit configured to receive, from a surveillance system via network, one or more surveillance logics to be executed to analyze an image of a target for surveillance; a surveillance program receiving unit configured to receive, from the surveillance system via the network, a surveillance program to carry out surveillance using the one or more surveillance logics; an image receiving unit configured to receive a captured image captured by a surveillance camera; a surveillance program execution unit configured to store the surveillance program received by the surveillance program receiving unit in a storage region of the surveillance device and activate or resume the surveillance program in response to a reception of the captured image; an image extraction unit configured to extract, from the captured image a plurality of target images to be analyzed by the one or more surveillance logics; a surveillance logic execution unit configured to store the one or more surveillance logics received by the surveillance logic receiving unit in the storage region of the surveillance device, call surveillance logics, among the one or more surveillance logics, to analyze the plurality of target images, and execute the called surveillance logics to analyze the plurality of target images; a surveillance result transmission unit configured to transmit, to the surveillance system via the network, a surveillance result obtained by analyzing the plurality of target images; a usage measurement unit configured to measure an execution amount of the surveillance logic called and executed by the surveillance logic execution unit; and an execution amount transmission unit configured to transmit, to the surveillance system via the network at a predetermined time interval or every predetermined number of times of the execution of the called surveillance logic, the measured execution amount to perform billing processing in accordance with the execution of the called surveillance logic, wherein the surveillance logic execution unit is configured to execute, among a plurality of the surveillance logics, the surveillance logic in accordance with a type of the target image, for each extracted target image. a surveillance logic receiving unit configured to receive, from a surveillance system via network, one or more surveillance logics to be executed to analyze an image of a target for surveillance; a surveillance program receiving unit configured to receive, from the surveillance system via the network, a surveillance program to carry out surveillance using the one or more surveillance logics; an image receiving unit configured to receive a captured image captured by a surveillance camera; a surveillance program execution unit configured to store the surveillance program received by the surveillance program receiving unit in a storage region of the surveillance device and activate or resume the surveillance program in response to a reception of the captured image; an image extraction unit configured to extract, from the captured image a plurality of target images to be analyzed by the one or more surveillance logics; a surveillance logic execution unit configured to store the one or more surveillance logics received by the surveillance logic receiving unit in the storage region of the surveillance device, call surveillance logics, among the one or more surveillance logics, to analyze the plurality of target images, and execute the called surveillance logics to analyze the plurality of target images; a surveillance result transmission unit configured to transmit, to the surveillance system via the network, a surveillance result obtained by analyzing the plurality of target images; a usage measurement unit configured to measure an execution amount of the surveillance logic called and executed by the surveillance logic execution unit; and an execution amount transmission unit configured to transmit, to the surveillance system via the network at a predetermined time interval or every predetermined number of times of the execution of the called surveillance logic, the measured execution amount to perform billing processing in accordance with the execution of the called surveillance logic, wherein the surveillance logic execution unit is configured to execute, among a plurality of the surveillance logics, the surveillance logic in accordance with a type of the target image, for each extracted target image.