A simulator for estimating a behavior of a system (1, 2) to be simulated, the simulator comprising: a creating unit configured to virtually create a virtual system including a virtual carrier in a three-dimensional virtual space, the virtual system including a virtual visual sensor virtually located at a first position on a virtual transporting path associated with the virtual carrier, and a virtual processing device virtually located at a second position on the virtual transporting path; a visual sensor simulator configured to perform image measurement of preliminarily obtained image data corresponding to processing performed using the virtual visual sensor; a controller simulator configured to generate a control instruction directed to the virtual processing device based on a measurement result obtained by the visual sensor simulator and to generate a read instruction directed to the visual sensor simulator for reading the image data; a storage unit configured to store the image data read in response to the read instruction in a manner associated with information indicating a position or a displacement of the virtual carrier, the position or the displacement serving as a reference for the image measurement performed in response to the read instruction; and a reproduction unit configured to reproduce a behavior of the virtual system based on time-series data provided from the controller simulator and the information associated with the image data stored in the storage unit, the reproduction unit generating and storing moving image data for reproducing the behavior of the virtual system, wherein the visual sensor simulator is configured to output, to the controller simulator, the measurement result together with the information indicating the position or the displacement of the virtual carrier associated with the image data used to generate the measurement result; and the controller simulator is configured to execute a control operation using a position of a target in the three-dimensional virtual space corrected based on the information indicating the position or the displacement of the virtual carrier provided together with the measurement result. a creating unit configured to virtually create a virtual system including a virtual carrier in a three-dimensional virtual space, the virtual system including a virtual visual sensor virtually located at a first position on a virtual transporting path associated with the virtual carrier, and a virtual processing device virtually located at a second position on the virtual transporting path; a visual sensor simulator configured to perform image measurement of preliminarily obtained image data corresponding to processing performed using the virtual visual sensor; a controller simulator configured to generate a control instruction directed to the virtual processing device based on a measurement result obtained by the visual sensor simulator and to generate a read instruction directed to the visual sensor simulator for reading the image data; a storage unit configured to store the image data read in response to the read instruction in a manner associated with information indicating a position or a displacement of the virtual carrier, the position or the displacement serving as a reference for the image measurement performed in response to the read instruction; and a reproduction unit configured to reproduce a behavior of the virtual system based on time-series data provided from the controller simulator and the information associated with the image data stored in the storage unit, the reproduction unit generating and storing moving image data for reproducing the behavior of the virtual system, wherein the visual sensor simulator is configured to output, to the controller simulator, the measurement result together with the information indicating the position or the displacement of the virtual carrier associated with the image data used to generate the measurement result; and the controller simulator is configured to execute a control operation using a position of a target in the three-dimensional virtual space corrected based on the information indicating the position or the displacement of the virtual carrier provided together with the measurement result.