A second detection unit detects a second gesture for switching between a rough adjustment mode in which the range of settable numerical values for a slide bar is a first range or/and the unit change width for a numerical value is a first change width and a fine adjustment mode in which the range is a second range narrower than the first range or/and the unit change width is a second change width narrower than the first change width. A mode switching unit switches between the rough adjustment mode and the fine adjustment mode in accordance with the second gesture. A display control unit causes a rough adjustment slide bar and a fine adjustment slide bar to be selectively displayed on an HMD.