A state display device capable of reducing a processing load applied to a microcomputer by performing part of a GUI process by hardware and a display method of the state display device are obtained. A rendering processing device starts a process in response to a rendering request stored in a rendering request region when a starting command is stored in a start/end instruction register. When a rendering request specified by an instruction address is a rendering termination request, the rendering processing means terminates the process performed in response to the rendering request, stores a termination factor in an interruption factor register, and issues an interruption to a central processing device.