1. An image acquiring apparatus comprising: macro image acquiring means for acquiring a macro image of a sample; dark field illuminating means to be used for acquiring a dark field macro image of the sample as the macro image; macro image processing means for processing image data of the macro image to generate a reference macro image; and image pickup condition setting means for setting an image acquiring range corresponding to a range including an object of image acquisition as an image pickup condition of a micro image of the sample by referring to the reference macro image, wherein the dark field illuminating means is installed as oblique illuminating means at a position on a side opposite to the macro image acquiring means with respect to the sample, for irradiating the sample with light obliquely with respect to an optical axis for acquiring the macro image and from the side opposite to the macro image acquiring means, such that the sample is placed at a position between the macro image acquiring means and the dark field illuminating means, and the macro image acquiring means includes a macro image pickup device capable of acquiring a two-dimensional image of the sample, and acquires the two-dimensional dark field macro image corresponding to a whole image of the sample in a single image acquisition.