PURPOSE: To make all feeding devices for an accumulative phosphor sheet installable in series quite at will, by making up both sheet receiving and discharging ports open to the outside at the same height of a device, while connecting them to each of discharging and receiving ports of other fellow devices.

CONSTITUTION: Sheet feeding devices 20, 30, 40 and 50 are all installed in a series state so as to cause each of discharging ports 26, 36 and 46 to accord with each of receiving ports 38, 48 and 58. Next, a magazine 23 in which accumulative phosphor sheets 2 are housed inside is installed in the sheet feeding device 20 at the upstream side, then each of sheets 2 is taken out of the magazine 23 piece by piece by means of vacuum force of a suction arm 24 and conveyed up to the sheet discharging port 26 through a conveying device 29. Next, these sheets 2 taken out of the discharging port 26 are transferred to the downstream side in regular sequence by transfer devices 39, 49 and 59 of the following sheet feeding devices 30, 40 and 50, and fed into a picture reading device 60. Likewise, those of sheets in other feeding devices 30 and 40 are all fed into this reading device 60 as well.