The present invention is directed to provide a semiconductor device having a dual-port memory circuit in which influence of placement of replica cells exerted on enlargement of chip area is reduced. A memory cell array of a dual-port memory circuit has: a first replica cell array used to respond to an instruction of reading operation from one of dual ports; and a second replica cell array used to respond to an instruction of reading operation from the other dual port. Each of the replica cell arrays has: replica bit lines obtained by mutually short-circuiting parallel lines having a length obtained by cutting, in half, an inversion bit line and a non-inversion bit line of complementary bit lines to which data input/output terminals of a memory cell are coupled; and replica cells coupled to the replica bit lines and having transistor placement equivalent to that of the memory cells.