[Object] To provide a compound which can be used for the treatment of a disease associated with fatty acid amide hydrolase (FAAH), particularly urinary frequency, urinary incontinence and/or overactive bladder.[Means for solution] It is confirmed that a urea compound chemical-structurally characterized by having a piperidine or piperazine ring or a salt thereof has an excellent FAAH-inhibitory activity, and thus the present invention is completed. The urea compound or its pharmaceutically acceptable salt of the present invention can increase the effective bladder capacity and ameliorate the state of urinary frequency, and is therefore useful as an agent for treating urinary frequency, urinary incontinence and/or overactive bladder.