The present invention relates to an LSI in which functions can be changed, and realizes, particularly, a system LSI in which functions are changed by changing connections of the circuit by use of MEMS switches. A bistable MEMS switch which can maintain states, and exhibits optimal stitching property, i.e., the switch has a very small resistance of several Ω or less in an on-state, and has an infinite resistance in an off-state; is employed. An element in which functions can be changed during operation, is produced by utilizing a wiring layer of a CMOS semiconductor to form the MEMS switch. A semiconductor device exhibiting high-degree of freedom for changing functions, high-speed, and having small area, is realized.