To smoothly perform paper sheet storing operation in a paper feeding cassette provided with an end guide guiding the rear end of the paper sheet.

This image recording medium feeder includes: the end guide 13c which is arranged displaceably in the paper sheet delivering direction of a body section 13-1 provided with a storage chamber 13b storing the paper sheet and which is provided with a guide surface 13c-1 guiding the rear end of the paper sheet stored in the storage chamber 13b; a second coil spring 53 pressing the end guide 13c to the paper sheet delivering direction to bring the guide surface 13c-1 into pressure contact with the rear end of the paper sheet; and a restraining plate 51 which is located in a first position perpendicularly restraining the end guide 13c with respect to the bottom surface 13b-1 of the storage chamber 13b against pressing force of the second coil spring 53 when the paper feeding cassette 13 is pulled out from a device body 10 and which is located in a second position allowing the pressing force of the second coil spring 53 when the paper feeding cassette 13 is fitted to the device body 10.