An alignment apparatus for mask and wafer each having alignment marks provided in a narrow strip like area between circuit patterns is disclosed, which mask and wafer are used in manufacturing semiconductor circuit elements. In the apparatus, the mask and wafer are scanned to obtain scan signals by means of which the amount of relative deviation between the alignment marks on mask and wafer is detected. By means of the detected signal, an alignment is effected between the mask and wafer in the apparatus. For this type of alignment apparatus, there is a problem that since the alignment marks are provided in the narrow strip like area, no coincidence between the scanning position and the strip area is attainable with pre-alignment accuracy. Improvement in the alignment apparatus according to the invention lies in that a reading of alignment marks is initiated after the coincidence is photoelectrically detected.