An input device comprising: an input unit for inputting a motion of an operator as an image signal; a motion detector for detecting the motion on the basis of the image signal inputted into the input unit; a display unit for displaying a graphical user interface; and a controller for causing the display unit to change a display of the graphical user interface according to the motion detected by the motion detector, wherein: the controller is configured to cause the display unit to display an operational guide that explains to the operator an operation starting gesture necessary to start an operation of the input device; when the controller recognises the motion detected by the motion detector as being the operation starting gesture explained by the operational guide, the controller is configured to cause the display unit to display, instead of the operational guide, a gesture operational menu (301, 302) and a motion guide that explains to the operator a second gesture for operating the gesture operational menu (301, 302); the motion guide includes animation corresponding to the second gesture; and when the controller recognises the motion detected by the motion detector as being the second gesture explained by the motion guide, the gesture operational menu (301, 302) is operated by the second gesture, wherein the controller causes the display unit to display a motion synchronized with the second gesture and also to change the display of the gesture operational menu (301, 302) in accordance with the second gesture. an input unit for inputting a motion of an operator as an image signal; a motion detector for detecting the motion on the basis of the image signal inputted into the input unit; a display unit for displaying a graphical user interface; and a controller for causing the display unit to change a display of the graphical user interface according to the motion detected by the motion detector, wherein: the controller is configured to cause the display unit to display an operational guide that explains to the operator an operation starting gesture necessary to start an operation of the input device; when the controller recognises the motion detected by the motion detector as being the operation starting gesture explained by the operational guide, the controller is configured to cause the display unit to display, instead of the operational guide, a gesture operational menu (301, 302) and a motion guide that explains to the operator a second gesture for operating the gesture operational menu (301, 302); the motion guide includes animation corresponding to the second gesture; and when the controller recognises the motion detected by the motion detector as being the second gesture explained by the motion guide, the gesture operational menu (301, 302) is operated by the second gesture, wherein the controller causes the display unit to display a motion synchronized with the second gesture and also to change the display of the gesture operational menu (301, 302) in accordance with the second gesture. the controller is configured to cause the display unit to display an operational guide that explains to the operator an operation starting gesture necessary to start an operation of the input device; when the controller recognises the motion detected by the motion detector as being the operation starting gesture explained by the operational guide, the controller is configured to cause the display unit to display, instead of the operational guide, a gesture operational menu (301, 302) and a motion guide that explains to the operator a second gesture for operating the gesture operational menu (301, 302); the motion guide includes animation corresponding to the second gesture; and when the controller recognises the motion detected by the motion detector as being the second gesture explained by the motion guide, the gesture operational menu (301, 302) is operated by the second gesture, wherein the controller causes the display unit to display a motion synchronized with the second gesture and also to change the display of the gesture operational menu (301, 302) in accordance with the second gesture.