SWINGING MECHANISM

PURPOSE: To provide a swinging mechanism for a scanning apparatus of which fluctuation degree of swinging angle is low even if the ambient temperature changes. CONSTITUTION: Regarding a swinging mechanism provided with a swinging plate 10 so stored in a frame 20-1 as to swing freely, a pair of electromagnets 25 which make the swinging plate 10 start swinging movement, and a pair of stoppers which are attached to the frame 20-1 and regulate the terminal positions of the swinging movement of the swinging plate 10 by bringing the tip end parts into contact with a reception plate 35-1 installed at a prescribe position of the swinging plate 10; the materials for the swinging plate 10, the frame 20-1, and the stopper main bodies 30-1 are materials having the same coefficient of thermal expansion and a hard member is fixed in each tip end part of the stopper main bodies 30-1.