Provided is an electromagnetic wave sensor including a thin metal plating layer to prevent an inflow of a fluid into the electromagnetic wave sensor and a method of generating the electromagnetic wave sensor, in which the electromagnetic wave sensor includes a waveguide including a conductor to sense an electromagnetic wave, a ceramic layer accommodated in the waveguide and including a dielectric to reduce a dielectric loss of the electromagnetic wave, and the thin metal plating layer disposed between the waveguide and the ceramic layer to prevent the inflow of the fluid into the electromagnetic wave sensor.
