Method for producing a carrier substrate, carrier substrate and electrochemical device

The method involves producing an open-pored and fluid-permeable support material (122) i.e. oxide forming material, which includes pores (124) forming a cavity (126) in the support material. A protection layer (130) is produced at an inner surface (128) of the support material by superficial oxidation of the support material, where the inner surface defines the cavity. An electron-conductive structure (134) extending within the cavity of the support material is produced. The electron-conductive structure is formed from a ceramic material. Independent claims are also included for the following: (1) a support substrate (2) an electrochemical device.