The object is to provide: an antimicrobial agent against Listeria monocytogenes, which has been believed to be a causative bacterium for listeriosis, an acidophilic bacterium such as Alicyclobacillus acidoterrestris, and a mold; and an anti-bacterial agent having a more potent anti-bacterial effect against a broader range of bacteria compared with conventional anti-bacterial agents. An antimicrobial agent having an antimicrobial effect against Listeria monocytogenes, an acidophilic bacterium and a mold can be provided by using lysophosphatidylglycerol as an active ingredient. An anti-bacterial agent having a potent anti-bacterial effect against a broader range of bacteria can be provided by using lysophosphatidylglycerol in combination with a conventional anti-bacterial agent.