Currently available β-lactamase inhibitors have an inadequate effect against β-lactamases, which continue to increase constantly. There is a need for novel β-lactamase inhibitors which can be used in the treatment of bacterial infections caused by resistant bacteria that are currently difficult to treat and that produce: class C β-lactamase； extended-spectrum β-lactamase (ESBL) belonging to classes A and D； KPC-2, which decomposes even carbapenem, the last bastion of β-lactam antibiotics, belonging to class A； and the like. Provided are a compound shown by formula (I), a method for producing the same, a β-lactamase inhibitor, and a method for treating bacterial infections.
