A semiconductor memory device includes a program and read unit suitable for programming program data in a memory cell array and for reading read data stored in the memory cell array, and a control unit suitable for generating a control signal for controlling the program and read unit in response to a command input from the outside of the semiconductor memory device, in which the control unit controls the program and read unit to read the read data in a state of storing a first bit data of the program data when a read command is input while programming the program data.