An electro-optical device is provided wherein a plurality of electronic components is integrally mounted on a circuit board and the circuit board is then connected to an FPC board. In the FPC board, a protrusion portion extending in the length direction of the FPC board is formed, and terminals of the protrusion portion and terminals of the circuit board are connected to each other in a state where an end of the circuit board overlapping the surface of a main body of the FPC board enters the back surface side of the protrusion portion and thus the protrusion portion overlaps the circuit board, so that the circuit board is disposed to intersect the protrusion portion.