Abstract: The present invention relates to an optically active, substituted phenylalkylamine derivative represented by Formula [1]: ##STR1## wherein A is a substituted or non-substituted phenyl or thienyl; X.sup.1 is hydrogen, halogen, hydroxyl or a substituted or non-substituted C.sub.1-5 alkoxy; R.sup.1 and R.sup.2 are equally or differently hydrogen, C.sub.1-7 alkyl, C.sub.3-7 alkenyl or C.sub.3-7 alkynyl; R.sup.3 is C.sub.1-10 alkyl, C.sub.2-10 alkenyl or C.sub.2-10 alkynyl; n is an integer from 2 to 5; and m is an integer from 1 to 4,or a pharmaceutically acceptable salt thereof, and pharmaceutical use of such compound or salt. The compound of the invention is excellent in sigma 1 receptor antagonism and useful for treating schizophrenia, depression, anxiety, cerebrovascular diseases/senile troublesome behaviors, and cognitive dysfunctions and motor dysfunctions such as Alzheimer's disease, Parkinson's disease and Huntington's disease which are neurodegenerative diseases.