An orally administrable antibacterial agent which contains as an active ingredient a carbapenem compound represented by the formula [1] below, wherein R0 represents hydrogen atom or the like; R1 represents C1-C3 alkyl substituted by hydroxyl group or the like; R represents hydrogen atom or a group which regenerates a carboxyl group by hydrolysis in a living body; L represents a single bond, methylene, —OCH2(CO)— or the like; and Het represents a group represented by the following formula [2], wherein m and n independently represent 0 or 1; A and B independently represent methylene, carbonyl or the like; Y represents methylene, ethylene, oxygen atom, —OCH2—, —NRaCH2— (wherein Ra represents hydrogen atom, optionally substituted C1-C4 alkyl group or the like) or the like.