Microwave dielectric properties and the microstructure of $Ba_5Nb_4O_{15}$ ceramics with $PbO-B_2O_3-SiO_2$ glass frit were investigated to reduce the sintering temperature of $Ba_5Nb_4O_{15}$ ceramics as a function of the amount of glass frit from $0.5wt\%$ to $10wt\%$ and the sintering condition. The sintered density and the microwave dielectric properties of $Ba_5Nb_4O_{15}$ ceramics were remarkably changed with the amount of glass fit which existed as a liquid phase and assisted the densification. $Ba_5Nb_4O_{15}$ with $3wt\%$ $PbO-B_2O_3-SiO_2$ glass frit sintered at $900^{circ}C$ for 2 h showed dielectric constant (K) of 41.4, a quality factor (Q $ imes$f) of 13,485 GHz, and a Temperature Coefficient of resonant Frequency (TCF) of 9 ppm/$^{circ}C$. Due to no trace of physical and chemical reaction between this composition and Ag electrode cofired at $900^{circ}C$ for 2 h, this ceramics can be a good candidate for the multilayer dielectric filter.