Epitaxial thin films of 5 mol% Y-doped BaZrO₃ (BZY5) proton conducting oxide were fabricated on MgO and Nb-doped SrTiO₃ single crystal substrates using PLD method. Crystal structure, microstructure and electrical properties in in-plane and perpendicular directions of those films were studied. BZY5 is grown epitaxially over 700^oC, and its epitaxial relationship is typical “Cube on Cube type”. TEM and AFM observations reveal that the films consist of columnar structure. Electrical properties in in-plain direction show significant lower conductivity and higher activation energy than that in perpendicular direction, and the properties are close to that of grain boundary in ceramics, while the electrical properties in perpendicular direction are similar to that of bulk in ceramics. These results suggest that the interfaces between columnar crystals even in epitaxial thin films prevent proton migration as the grain boundaries in ceramics do.