Use of an intense and narrow linear‐shaped x‐ray source is essential to improve the quality of the extended x‐ray absorption fine‐structure measurements in a laboratory. To this end, an x‐ray generator with a large rotating anode, designed for dedicated use of point‐shaped focal spot, was modified to provide a linear‐shaped focal spot of ∼0.1 mm in width at an exit angle of 6°. The maximum allowable current was 600 mA, which has never been realized so far using a conventional x‐ray linear focal spot.