An ignition coil device mounted on the cylinder head of an internal combustion engine. The ignition coil includes: a cylindrical pipe inserted into a plug hole while a first clearance is formed between the cylindrical pipe and the plug hole; a coil tower arranged over the cylindrical pipe; a seal member arranged below the coil tower for sealing the plug hole; and a cover arranged between the seal member and the coil tower. The seal member is formed with an air bleeding hole extending from the first clearance to a side of the coil tower. The air bleeding hole includes a protruding opening. A circumferential wall portion is positioned on the outer circumference side of the protruding opening while a second clearance is formed between the cover and a periphery of the protruding opening.