A semiconductor integrated circuit device

A semiconductor integrated circuit device comprising a memory cell array (13) containing a plurality of spaced rows and columns of memory cells, a first internal power supply means (11) for receiving an external power supply voltage (Ext.Vcc) and for generating a first internal power supply voltage (Vcc1), which is lower than the external power supply voltage (Ext.Vcc), a sense amplifier (25) that receives the first internal power supply voltage (Vcc1) for working, for amplifying one of a memory cell in the memory cell array (13) data read out signal, a second internal power supply means (12) for receiving the external power supply voltage (Ext.Vcc) and for generating a second internal power supply voltage (Vcc2), which is lower than the external power supply voltage (Ext.Vcc), and a write driver (23) that receives the second internal power supply voltage (Vcc2) for working, for writing a data signal in a memory cell (32) in the memory cell array (13).