Abstract: A condensed thiophene compound of the formula (I) wherein each symbol is as defined in the specification, a pharmaceutically acceptable salt thereof and hydrates thereof. The compound of the formula (I) of the present invention is useful as a novel antipsychotic agent which is effective for both positive symptoms and negative symptoms of schizophrenia, which is associated with less side effects such as extrapyramidal motor disorder and the like and which is less associated with serious side effects such as agranulocytosis and the like. In addition, this compound is also useful as a therapeutic agent of Alzheimer's disease and manic-depressive illness.