This paper reports on the observation of an interplanetary slow shock on May 23, 1995 using 3-s plasma and magnetic field data from the Wind spacecraft. Since the time to traverse the shock (~15 s) is much greater than the 3-s temporal resolution of the data, this observation can reveal the plasma and magnetic field structure through the interior of the shock. The 3-s data also provide accurate preshock and postshock conditions immediately outside the shock layer. The flow speeds in the shock frame of reference UnCS1, and Un2S2. Here a and CS are, respectively, the Alfven speed and the slow speed, &THgr; is the acute angle between the magnetic field vector and the shock normal, and the subscripts 1 and 2 denote the preshock and the postshock conditions. &THgr;1~47¿ and &THgr;2~39¿. The jump conditions B2/B1, N2/N1, and (Ti+Te)2/(Ti+Te)1 of the observational result are in good agreement with the Rankine-Hugoniot solution. The thickness of the shock is of the order of 36 times of the preshock ion inertial length. ¿ 1998 American Geophysical Union