A comparative study has been attempted for microwave and conventional sintering of lead-free $Bi_{0.5}Na_{0.5}TiO_3(BNT)$-based multilayer ceramic actuators(MLAs). It was found that microwave sintering (MWS) could be successfully applied to the co-firing of piezoceramic/AgPd MLAs with a 10 times shorter firing cycle as well as $100^{circ}C$ lower firing temperature ($850^{circ}C$) for sufficient densification than conventional furnace sintering ($950^{circ}C$). Furthermore, MWS-derived specimens showed better electric field-induced strain than that of CFS-derived specimens by effectively suppressing interdiffusions between ceramic and electrode layers.