An NMR sample tube for NMR measurement is provided. It includes a plug on both sides or one side of a sample to be measured, in an axial direction of the sample tube. The plug is adjusted to have magnetic susceptibility equal to or substantially equal to that of the sample. A whole shape of the plug and a sample space together is axisymmetric about an axis of the sample tube, and a surface of the plug not abutting the sample space bulges in a direction away from the sample space.