An overhead scanner 1 includes an imaging unit 22 that images a medium S placed on a mount surface 2 to be read from above and a light source 21 that is arranged to be able to irradiate the medium S with light during imaging by the imaging unit 22. A control device 40 of the overhead scanner 1 performs anti-glare control when detecting that the medium S is glossy. This prevents glare from occurring to the user during operation of the overhead scanner 1.