A semiconductor memory device using a clock of a constant period supplied from the exterior of a memory chip and a sense amplifier for reading out data from a memory cell designated by an address includes at least two different delay circuits for setting at least two delay time periods from the clock, a selecting circuit for receiving signals generated from the delay circuits and selecting one of said signals by a given control signal, and a data output buffer for receiving the data generated from the sense amplifier by a signal generated from the selecting circuit.