Fluorine-substituted piperidine compound

The fluorine-substituted piperidine compound represented in formula (I) or a pharmaceutically acceptable salt thereof is useful in the treatment or prevention of disorders that are on the basis of orexin (OX) receptor antagonism including sleep disorders, depression, anxiety disorders, panic disorders, schizophrenia, drug dependence, Alzheimer's disease, Parkinson's disease, Huntington's disease, eating disorders, headaches, migraines, pain, gastrointestinal diseases, epilepsy, inflammation, immunological disorders, endocrine disorders, and high blood pressure.