PURPOSE: To increase the reading speed of a mask type read-only storage circuit ROM, by providing a switch circuit to an ROM in order to decide the in- phase or antiphase to deliver the output of the ROM.

CONSTITUTION: A TF digit is provided to the read-only storage circuit (a mask type ROM) to decide the in-phase or antiphase to deliver a digit line DLn to a data output Dn. This TF digit consists of a load MOSDTRTF, a memory data transistor TRTF to An and an equivalent capacity CTF. Thus the reading speed is increased for the mask type ROM.