To provide a field emission cathode that can emit electrons at a low voltage and can increase a field emission current.

In this field emission cathode, a cathode 1, an insulating layer 2 and a gate electrode 3 are laminated on a glass or ceramic substrate 8. Then, an opening (hole) 4 is formed in the insulating layer 2 and the gate electrode 3, and for instance, a cone-like emitter chip 5 is formed on the cathode 1 in its inside. The emitter chip 5 is a metal chip such as Mo having a small resistivity. The surface of the emitter chip 5 is thinly covered with a modified photoresist 6. The modified photoresist 6 is so formed that a photoresist 7 is provided with carbon-carbon bond by Ar+ ion irradiation or heat treatment in vacuum.