A semiconductor memory device has a plurality of memory cell arrays (12a,12b); input and output sections (11a, 11b) each provided so as to correspond to each of the memory cell arrays; and an allocating section (17) provided between the memory cell arrays and the input and output sections, for allocating one of the memory cell arrays to one of the input output sections in ordinary mode, and a plurality of the memory cell arrays to one of the input and output sections in test mode. In the operation test mode, since only a part of the input and output sections are used, it is possible to decrease the number of chips connected to the I/O pins (whose maximum number is limited) of the tester so as to be testable simultaneously, so that the number of chips whose operation tests can be implemented simultaneously can be increased, thus reducing the time required for the operation test of the memory device as a whole.