PROBLEM TO BE SOLVED: To provide a monitoring device capable of displaying an X-ray image by arranging respective display parts including respective rectangular display areas having each different aspect ratio in both directions of the longitudinal and lateral directions in accordance with a peripheral state.SOLUTION: A control part 70 includes an image processing part 71 for displaying an X-ray fluoroscopic image and an X-ray image simultaneously on a display part 40 in a monitoring device 2. The image processing part 71 has an image rotation part 72 for rotating the X-ray fluoroscopic image and the X-ray image to be displayed on a display area of the display part 40 based on rotation attitude of the display part 40 detected by a rotation support part 53 functioning as a rotation attitude detection part.SELECTED DRAWING: Figure 7
