A display device with high design flexibility that can be designed easily is provided. One embodiment of the present invention includes a first substrate (101) provided with a driver circuit including first and second pulse output circuits (91_1, 91_2), a second substrate (103) provided with a display unit (92) including a first pixel circuit including a first source wiring (SL_1) and a first contact portion (SC_1) and a second pixel circuit including a second source wiring (SL_2) adjacent to the first source wiring and a second contact portion (SC_2) electrically connected to the second source wiring, and a connection unit where the first and second substrates are electrically connected to each other. The display unit is placed to overlap with the driver circuit, the first and second pulse output circuits are electrically connected to the first and second pixel circuits respectively through the first and second contact portions, the first pulse output circuit is placed on an opposite side of a straight line connecting the first and second contact portions from the second pulse output circuit, and the connection unit includes a wiring containing copper.