The purpose of the present invention is to provide crystals of a compound that exhibits an analgesic action against neuropathic pain and/or fibromyalgia, the crystals being useful as pharmaceuticals. The present invention provides crystals of (S)-1-(4-(dimethylamino)piperidin-1-yl)-3-hydroxy-3-(1-methyl-1H-imidazol-2-yl)propan-1-one or a pharmacologically acceptable salt thereof.本發明係以提供對神經性病變疼痛及/或肌纖維痛症顯示鎮痛作用的化合物之有用於作為醫藥品的結晶為目的。本發明係提供(S)-1-(4-(二甲基胺基)哌啶-1-基)-3-羥基-3-(1-甲基-1H-咪唑-2-基)丙烷-1-酮或其藥理學上可容許的鹽之結晶。
