PURPOSE: To obtain an image reader which can easily obtain a high quality image output by deteriorating resolution concerning a subscanning direction to an image signal before/after the point of time when a subscanning operation is interrupted.

CONSTITUTION: An image signal processing circuit 5 outputs digital image data supplied to an input terminal (a) from a signal processing part 2 to an output terminal (b) as it is in accordance with a control signal Sc provided to a terminal (c) from a buffer memory circuit 6 and outputs digital image data at the section of a previously specified range before/after the point of the time when the subscanning operation is interrupted to the output terminal (b) as digital image data in a state where resolution concerning the subscanning direction is deteriorated. When the subscanning operation is interrupted and restored while reading an original, resolution concerning the subscanning direction is deteriorated so that the state of the deterioration of an image caused by the change of the pitch of subscanning before/after the point of the time when the subscanning operation is interrupted is reduced.