An image processor wherein a radiation image forming device forms a radiation image corresponding to the radiation amount transmitted through an object, a discriminator discriminates at least one of the region of the object and the radiographing orientation for a radiation image, and an image processing condition memorizing device memorizes each of a plurality of image processing conditions in accordance with each of the regions of an object, each of the directions of radiographing, or each of the combinations of both of these. At least one image processing condition is displayed, and an image processing condition selects an arbitrary image processing condition out of the displayed image processing conditions. At least one image processing condition is read out from the image processing condition memorizing device based on the result of discrimination obtained by the discriminator and is displayed, and the selecting of an arbitrary image processing condition out of the displayed image processing conditions is accepted.