Methylene Blue (MB) was adsorbed in zirconium(IV), phosphate by means of an ion exchange reaction. The dye is strongly retained and not easily leached from the matrix. The material with the adsorbed dye was incorporated into a carbon paste electrode and by means of cyclic voltammetry and amperometry, the electrochemical property was investigated. In various electrolyte solutions and changing the pH between 2.5 and 6, the midpoint potential remained practically constant, i.e., 0.15+/-0.01 V. This is not the usual behavior of MB, since it is known in solution phase that its midpoint potential changes considerably as the pH changed. It appears that the Methylene Blue is a guest molecule in the lamellar structure of the zirconium phosphate. The electrode made with this material was used to study the electrochemical oxidation of ascorbic acid.910800803