As a result of studies on compounds having a selective inhibitory activity against 17βHSD type 5, the present inventors have confirmed that a {1-[(indol-2-yl)carbonyl]piperidyl}alkanol derivative has a potent selective inhibitory activity against 17βHSD type 5. The invention has been completed based on these findings. The compound of the present invention can be used as an agent for treating and/or an agent for preventing diseases associated with 17βHSD type 5, such as benign prostatic hyperplasia and prostate cancer, without accompanying adverse effects due to a decrease in testosterone.
