[Problem] A compound which is useful as an IK1 channel activator is provided. [Means for Solution] As a result of studies on the IK1 channel activator, the present inventors have found that a benzothiophene compound shows effectiveness on visceral pain, inflammatory pain, osteoarthritis pain, neuropathic pain, or fibromyalgia, thereby completing the invention. A compound of the invention has an IK1 channel activation effect, and can also be used as an agent for preventing and/or treating visceral pain, inflammatory pain, osteoarthritis pain, neuropathic pain, or fibromyalgia. In addition, the IK1 channel activator can be used as an agent for preventing and/or treating inflammatory pain, osteoarthritis pain, neuropathic pain, and fibromyalgia.