As a result of studies on compounds having a selective inhibitory activity against 17²HSD type 5, the present inventors have confirmed that a {1-[(indol-2-yl)carbonyl]piperidyl}alkanol derivative has a potent selective inhibitory activity against 17²HSD 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 17²HSD type 5, such as benign prostatic hyperplasia and prostate cancer, without accompanying adverse effects due to a decrease in testosterone.
