<p>Disclosed is a novel process for producing a 1ß-methylcarbapenem compound by culturing a microorganism. A 1ß-methylcarbapenem compound can be produced by culturing a microorganism capable of producing a carbapenem compound, particularly a thienamycin-producing microorganism, in a culture medium supplemented with a (2S,4S)-4-methylglutamic acid analogue and isolating the 1ß-methylcarbapenem compound from the culture. The 1ß-methylcarbapenem compound is useful as a pharmaceutical agent or a raw material for a pharmaceutical agent.</p>
