Bartonellosis is spotlighted recently as an emerging zoonosis and $Bartonella$ $henselae$ is reported to be the main infectious agent. In Korea, however, few studies have been made on the epidemiology and microbiology on bartonellosis. Thus, this study was conducted to produce a new monoclonal antibody that can be used for identifying $B.$ $henselae$. In order to prepare monoclonal antibodies against $B.$ $henselae$, we inoculated mice with the isolated strain from Korean patient and performed cell fusion experiment. The selected hybridoma clones produced monoclonal antibodies which showed positive immunofluorescence staining of bacteria and specific protein bands in western blot analysis. In order to examine whether these antibodies could be used for the identifying and quantifying $Bartonella$, we performed confocal microscopy and flow cytometry using the new antibodies. These monoclonal antibodies can be used as a useful tool in further researches on the biology of $Bartonella$.