A semiconductor memory device is operated by, inter alia, sequentially inputting program data to page buffers coupled to selected pages of at least four planes in order to program selected memory cells included in the selected pages; performing a program operation on each of the four planes; performing a program verify operation on each of the four planes; and inputting new program data for next pages to the page buffers coupled to the next pages, after determining the selected pages of at least two of the four planes have passed the program verify operation, while performing the program operations and the program verify operations on the two remaining planes.