To solve such a problem in an electromagnetic driving device for driving the opening/closing of the suction valve that the device itself is enlarged if the valve element lifting amount of a suction valve or the like is formed to be adjusted by changing the position of an electromagnetic coil wound on an iron core for driving a moving piece.

This electromagnetic driving device for a valve element of an internal combustion engine acts the electromagnetic force generating when voltage is applied to the electromagnetic coil wound on an iron core to a moving piece locating in a space within the iron core, and drives the valve element of the internal combustion engine with a driving shaft interlocking with the moving piece. The moving piece is formed so that the thickness is changeable according to the inner dimension of the space within the iron core.