Its pharmaceutical composition, production method and use as bacteria. 1. Characteristic 1: a 2,3-dihydro-6-nitromidazo [2,1-b] oxazol compound, whose characteristic is represented by a general formula (1),the optically active form thereof, or a pharmaceutically acceptable salt thereof, wherein R¹ represents a hydrogen atom or C₁₋₆ alkyl group,N represents an integer from 0 to 6, R 2 represents a phenol group represented by the general formula (2),wherein X represents a halogen atom or C₁₋₆ alkyl group substituted by amino which may have a C₁₋₆ alkyl group as a substituent, m represents an integer from 0 to 3, and R¹¹ represents: E1) hydrogen atom； E2) C₁₋₆ alkyl group unsubstituted or substituted by halogen； E3) C₁₋₆ alkoxy group substituted or unsubstituted by halogen； E4) a group represented by the general formula: - (W) ₒ-NR¹²R¹³ where W represents a -CO- group or a C₁₋₆ alkylene group,or represents an integer of value 0 or 1, and R¹² and R¹³ are the same or different and each represents any of: (Ea1) hydrogen atom； (Ea2) C₁₋₆ alkyl group；(Ea3) grupo alcanoilo C(Ea4) grupo alcoxicarbonilo C(Ea5) C₁₋₆ phenylalkyl group (which may be substituted on the phenyl ring by at least one group selected from the group consisting of a halogen atom, a C₁₋₆ alkyl group unsubstituted or substituted by halogen, a C₁ alkoxy group ₋₆ unsubstituted or substituted by halogen, and a phenoxy group (which can be substituted on the phenyl ring at least by a group selected from the group consisting of a halogen atom, a C₁₋₆ alkyl group unsubstituted or substituted by halogen , and a C₁₋₆ alkoxy group unsubstituted or substituted by halogen as a substituent),and a C₁₋₆ alkoxyimino group can be substituted by the alkyl portion)；(Ea6) phenyl group (which may be substituted on the phenyl ring by at least one group selected from the group consisting of a halogen atom, a C₁₋₆ alkyl group unsubstituted or substituted by halogen, and a C₁₋₆ alkoxy group not substituted or substituted by halogen
