A novel programmable logic device is provided. Programmable switches each include a first transistor and a second transistor. The first transistor in a first programmable switch controls conduction between a first wiring and a gate of the second transistor in the first programmable switch. The second transistor in the first programmable switch controls conduction between the first wiring and a second wiring. The first transistor in the second programmable switch controls conduction between another first wiring and a gate of the second transistor in the second programmable switch.