A moving image splitting device is connected to the cameras of a camera group that captures moving images, connected to an information processor through a network, and having a processor. The processor repeats requesting the camera to send a moving image, acquiring a captured moving image from the camera, detecting an I frame from the acquired moving image, creating split data with a sequence allocated in an ascending order of captured time instants in a GOP unit including the I frame, and accumulating the split data in a storage device. In response to a request for split data from the information processor, the processor extracts split data from the storage device with reference to the sequence allocated to the split data, and transfers the extracted split data to the information processor.