A sample holder is provided allowing for favorable observation of a cross-sectional sample using a retarding method. The sample holder includes: a sample placement member on which a first fixing member, a cross-sectional sample as an observation sample, and a second fixing member are placed in contact with each other, and inserted inside the electronic optical lens barrel of an electron microscope; and a voltage introduction means for introducing a voltage to the sample placement member. The sample placement member has a positioning section for positioning the first fixing member, the cross-sectional sample, and the second fixing member onto a placement position. A positioning section positions the first planar surface of the first fixing member and the second planar surface of the second fixing member which are disposed respectively adjacent to the observation surface of the cross-sectional sample, parallel to the observation surface at locations equidistant from the observation surface.