Abstract: An electronic paper display device, which retains a display state even when power is off, is installed outside a server main body. A display control unit provided as software in the server main body displays the information, which indicates a substance of the abnormality detected in the server main body, for example, an error code indicating the substance of the abnormality, in the electronic paper display device. Even when power is turned off after the error code is displayed in the electronic paper display device due to failure of power or a cooling fan, the electronic paper display device maintains display of the error code even after the power-off by memory property of electronic paper.