1. A monitor system including at least one monitor terminal and at least one monitor device, wherein the monitor terminal includes an image-pickup unit configured to pick up an image of a monitor subject and generate video data; and a meta-data-generation unit configured to generate meta data indicating attribute information of the monitor subject of which image is picked up by the image-pickup unit, wherein the monitor device includes a video-data-accumulation unit configured to store the video data transmitted from the image-pickup unit; a search-criteria-storage unit configured to store search criteria in advance, the search criteria being used, so as to extract desired data from video data accumulated on the video-data-accumulation unit and meta data accumulated on the meta-data-accumulation unit; a display unit configured to display the search criteria stored in the search-criteria-storage unit; and a control unit configured to extract meta data satisfying a predetermined search criterion when the predetermined search criterion is selected from among the search criteria displayed on the display unit, and display the extracted meta data on the display unit.