An electro-optical device includes a first drive IC and a second drive IC which are respectively mounted on a first flexible wiring substrate and a second flexible wiring substrate in a first mounting substrate and a second mounting substrate (first substrate). A first extension substrate and a second extension substrate (second substrate) which are configured by a flexible wiring substrate are connected to end portions of the first mounting substrate and the second mounting substrate, and a first protective film and a second protective film are attached to both surfaces in connection portions. The first protective film and the second protective film extend to positions covering the first drive IC and the second drive IC.