An insoluble electrode is characterised in that a uniform coating layer composed of titanium oxide and at least one base metal has been applied to an electrically conducting substrate by flame spraying. The present invention also provides an electrochemical apparatus which employs the insoluble electrode as anode and which contains an electrolyte between said insoluble anode and the cathode in such a way that an electrochemical reaction is able to take place between the two electrodes. Said uniform spray coating is not a simple mixture of titanium oxide and another base metal (or base metals) but it has the structure of a solid solution, a composite oxide or a eutectic mixture of both components, or it is composed of a combination of two or more such structures.
