A projector (1) which projects a guide image (Pg). A first region above the center of the guide image (Pg) shows a perspective view (D) representing the projector (1) and a supporting device (2) supporting the projector (1). A second region on the upper right of the guide image (Pg), shows six illustrations (G1-G6) affixed with numbers 1 to 6. The six illustrations (G1-G6) respectively correspond to six adjustment items related to a supporting state of the projector (1). The six illustrations (G1-G6) indicate how a projected image changes when the adjustment items are adjusted. The perspective view (D) is an explanatory diagram for clearly showing the positions of adjustment operation units that adjust the six adjustment items of the supporting device (2). In the perspective view (D), the numbers 1 to 6 are affixed near the respective adjustment operation units in balloons.