Disclosed is a therapeutic agent effective for malignant mesothelioma. Specifically disclosed is a therapeutic agent for mesothelioma, which comprises a calponin-targeting oncolytic herpes simplex virus (HSV-1) mutant, preferably strain d12.CALPfΔRR. Also disclosed is a method for producing a cell for use in the treatment of mesothelioma, which is characterized by infecting a mesothelioma cell removed from a patient with a herpes simplex virus F-type mutant which can proliferate in a calponin gene-targeting manner, preferably strain d12.CALPfΔRR. Further disclosed are: a cell produced by the method； and a calponin-targeting oncolytic herpes simplex virus (HSV-1) mutant, preferably strain d12.CALPfΔRR.
