A device for controlling the operation of an internal combustion engine, comprising: an inlet valve operating lever support rotationally supported, the inlet valve operating lever support being provided with a first eccentric configured to support an inlet valve operating lever for controlling an inlet valve; an outlet valve operating lever support rotationally supported, the outlet valve operating lever support being provided with a second eccentric configured to support an outlet valve operating lever for controlling an outlet valve; a fuel injection operating lever support rotationally supported, the fuel injection operating lever support being provided with a third eccentric configured to support a fuel injection operating lever for controlling a fuel injection device; and a shaft rotationally supported, the shaft being provided with a first engagement portion, a second engagement portion and a third engagement portion, the first engagement portion being configured to engage with the inlet valve operating lever support to rotate the same between a first inlet valve operating position and a second inlet valve operating position, the second engagement portion being configured to engage with the outlet valve operating lever support to rotate the same between a first outlet valve operating position and a second outlet valve operating position, and the third engagement portion being configured to engage with the fuel injection operating lever support to rotate the same between a first fuel injection operating position and a second fuel injection operating position, at least two of the inlet valve operating lever support, the outlet valve operating lever support and the fuel injection operating lever support being configured to rotate independent from each other, the at least two of the inlet valve operating lever support, the outlet valve operating lever support and the fuel injection operating lever support, and the associated engagement portions of the shaft being configured to engage with each other at different rotational positions of the shaft. an inlet valve operating lever support rotationally supported, the inlet valve operating lever support being provided with a first eccentric configured to support an inlet valve operating lever for controlling an inlet valve; an outlet valve operating lever support rotationally supported, the outlet valve operating lever support being provided with a second eccentric configured to support an outlet valve operating lever for controlling an outlet valve; a fuel injection operating lever support rotationally supported, the fuel injection operating lever support being provided with a third eccentric configured to support a fuel injection operating lever for controlling a fuel injection device; and a shaft rotationally supported, the shaft being provided with a first engagement portion, a second engagement portion and a third engagement portion, the first engagement portion being configured to engage with the inlet valve operating lever support to rotate the same between a first inlet valve operating position and a second inlet valve operating position, the second engagement portion being configured to engage with the outlet valve operating lever support to rotate the same between a first outlet valve operating position and a second outlet valve operating position, and the third engagement portion being configured to engage with the fuel injection operating lever support to rotate the same between a first fuel injection operating position and a second fuel injection operating position, at least two of the inlet valve operating lever support, the outlet valve operating lever support and the fuel injection operating lever support being configured to rotate independent from each other, the at least two of the inlet valve operating lever support, the outlet valve operating lever support and the fuel injection operating lever support, and the associated engagement portions of the shaft being configured to engage with each other at different rotational positions of the shaft.