To read radiation image information with a radiation image information reader using a line sensor by eliminating the influence of grid images.

This radiation image information reader has an exciting light irradiating means 11 which linearly irradiates part of a stimulus phosphor sheet 13 accumulated with the radiation image information through static grids with the exciting light 10, the line sensor 17 juxtaposed with plural photoelectric conversion elements so as to exist along the wire-shaped exciting light irradiation segment of the stimulus phosphor sheet 13 and a sub-scanning means 18. The line sensor 17 which is greater in the inverse number of the juxtaposition pitch of the photoelectric conversion elements than the value twice the space frequency relating to the direction of the juxtaposition of the stripe pattern-like grid images G recorded on the stimulus phosphor sheet 13 is used. The image signal D outputted from the line sensor 17 is subjected to filtering processing to remove the grid images G through a filtering means 22.