This paper deals with a metal strip grating (MSG) dihedral as a polarization selective target for polarimetric SAR calibration. An experiment was carried out for the radar cross section (RCS) characteristics for polarizations both parallel and perpendicular to the gratings and for polarization isolation ratio (PIR) characteristics by using a prototype MSG dihedral manufactured in our laboratory. Although the prototype includes many manufacturing errors in the grating and dihedral structures, the RCS decrease was only 1.1 dB relative to the theoretical prediction, and a PIR of 44.9 dB was attained. The results show promising characteristics of an MSG dihedral as a target for polarimetric calibration.