The present invention provides a 2,3-dihydro-6-nitroimidazo[2,1-b]oxazole compound represented by the following general formula: ##STR00001## wherein R.sup.1 represents a hydrogen atom or C1-C6 alkyl group, n represents an integer of 0 to 6, R.sup.2 represents a group --OR.sup.3 or the like, and R.sup.3 represents a hydrogen atom, C1-C6 alkyl group or the like, or R.sup.1 and --(CH.sub.2).sub.nR.sup.2 may bind to each other together with carbon atoms adjacent thereto through nitrogen atoms so as to form a spiro ring represented by the general formula (H): ##STR00002## wherein R.sup.41 is hydrogen, C1-C6 alkyl group or the like. The present compound has an excellent bactericidal action against Mycobacterium tuberculosis, multi-drug-resistant Mycobacterium tuberculosis, and atypical acid-fast bacteria.