A new high resolution X‐ray microscopy project is proposed at Saga synchrotron light source, a third generation synchrotron light facility in Kyusyu Island, Japan. Two microscopy beamlines are planned. One is a scanning microscope in the water window region and the other is a full‐field imaging microscope in the multi‐keV X‐ray energy region. To demonstrate the feasibility of the project, an optical layout of the scanning microscope was designed. The beamline mainly consists of a 3.5 cm periodical undulator, a varied line‐spacing plane grating monochoromator (600 lines/mm) and an end‐station including a zone plate. The calculated X‐ray properties focused on the sample position are as follows: the spot size is ∼70 nm, the monochromaticity is ∼2000, and the photon flux is 109∼ 1010photons/s. © 2004 American Institute of Physics