A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a diffusion prevention layer made of Co formed on the base, a coating of Ni powders formed on the diffusion prevention layer, and an electron emissive alkaline earth oxide layer formed on the coating of Ni powders, does not show deformation of Ni powders or peeling of the oxide layer during the production procedures or operation of the cathode.