According to one embodiment, a tilting mechanism includes a fixed section including a guide surface depressed in an arc shape; and a movable section having an outer peripheral surface curved in an arc shape that comes in contact with the guide surface of the fixed section and tilting along the guide surface, the movable section including a concave portion cut out to open the outer peripheral surface, wherein the concave portion includes a pair of side surfaces opposed to each other; and guide grooves that are curved along a curvature of the outer peripheral surface of the movable section and are formed on the side surfaces; and the fixed section includes a plurality of shafts that are slidably fitted into the guide grooves.