The present invention relates to 2-[4-[2-(7-trifluoromethylbenzoxazol-2-ylthio)ethyl]piperazin-1-yl]-N-[4-hydroxy-2,6-bis(trifluoromethyl)phenyl]acetamide or salt thereof, and an intermediate for the preparation thereof. The above-described compound has both an inhibitory action on ACAT in the artery wall and remarkably high metabolic resistance in human liver microsomes, and exhibits excellent effects for suppressing lipids depression in aorta in vivo so that it is useful as a highly effective preventive or remedy for hyperlipidemia and arteriosclerosis with less side effects.