The n-channel germanium junction field effect transistor (Ge-JFET) was designed and fabricated for cryogenic applications. Ideal device current and voltage characteristics were obtained at cryogenic temperatures down to the liquid helium temperature (4.2 K). The Ge-JFET exhibits a superior noise performance at the liquid nitrogen temperature (77 K). From the device current voltage characteristics of n-channel JFETs, it is seen that the transconductance increases monotonically with the lowering of temperature to 4.2 K.