detection voltage hvrf equal to the reference voltage vrf equations 1 and 2 given below are held on the assumption that the on resistances of the first and the second transistors 330 and 332 are negligible here r1 rr and rp respectively denote resistances of the first through the third resistors 324 326 and 328 as clearly understood from equations 1 and 2 given above the lower output voltage hv low for turning the first transistor 330 on and the higher output voltage hv high for turning the second transistor 332 on are independently set by regulating the resistances r 1 rr and rp of the first through the third resistors 324 326 and 328 in this embodiment according to the voltage setting conditions shown in the table of fig3 the lower output voltage hv low to turn the first transistor 330 on is set equal to 5 0 v in the read mode and in the standby mode in the program mode and in the erase mode the higher output voltage hv high to turn the second transistor 332 on is set equal to 8 0 v as described above in the booster circuit 260 the oscillation operation of the oscillation circuit 300 and the operation of the charge pump circuit 310 are controlled according to the level of the output voltage hv detected by the level sensor 320 the booster circuit 260 functions to make the output voltage hv from the charge pump circuit 310 equal to the lower output voltage hv low of 5 0 v in the standby mode and in the read mode and equal to the higher.