With the goal of establishing a new cancer treatment method using nanosecond pulsed electric fields (nsPEFs), we investigated the effect of applying nsPEFs and anticancer drugs (adriamycin, ADM) to cancer cells. The surviving fraction of cancer cells was significantly reduced by nsPEFs application compared to the control. Compared to nsPEFs alone and ADM administration alone, a significant decrease of the surviving fraction was observed in combination of nsPEFs application and ADM administration. In addition, multiplying value of surviving fractions of nsPEFs application and ADM administration was calculated as a pseudo-combination effect. The surviving fractions of the experimental combinational results of nsPEFs and ADM were lower than the pseudo-combination results. Therefore, the synergistic effect of combination of nsPEFs and ADM was confirmed. Furthermore, the surviving fraction of ADM administration after nsPEFs application was significantly lower than that of ADM administration on 24 hours before nsPEFs application. ADM action on cells would be effective owing to nanopores were formed by applying nsPEFs. It was confirmed that ADM and nsPEF induced apoptosis of cells from apoptosis and necrosis test using FACS.