[$SiO_2$] film coated as a passivation layer for YBCO based electronic devices is investigated by measuring the micro wave properties of micro strip line resonators. The $SiO_2$ film coated resonators are compared with coated resonators for two degradation conditions, a $200^{circ}C$ annealing in air and an exposure to air at $85^{circ}C;85\%$ relative humidity. The $SiO_2$ film reduces the YBCO thin film degradation caused by oxygen stoichiometry change and reaction with water.