The present invention provides a method of detecting dermatophyte, which does not require a complicated operation such as an enzyme treatment and a heat treatment.The present invention provides a method of detecting dermatophyte, including a step of extracting a dermatophyte component from a sample with a treatment liquid containing a non-ionic surfactant or a zwitterionic surfactant, and a kit for diagnosing dermatophyte infection, containing a treatment liquid comprising the above surfactant, and an antibody specifically recognizing a dermatophyte component, which are housed in separate containers.