An internal combustion engine (101, 601, 901) alters an effective compression ratio from an effective compression ratio for a start-up operation to a larger effective compression ratio for a normal operation when an engine rotation speed (NE) increases beyond a resonance rotation speed region during cranking. A controller (104, 610, 910) determines whether or not the engine (101, 601, 901) has reached a combustion possible state on the basis of the engine rotation speed (NE) during cranking and an operating parameter (PA, TA, TW, P_Rail, V_Ang) other than the engine rotation speed (NE) (S1102, S1202, S1204). When the determination is negative, the controller (104, 610, 910) inhibits fuel supply to the engine (101, 601, 901) by a fuel supply device (207), even when the engine rotation speed has increased beyond the resonance rotation speed region (S406). In so doing, a combustion defect such as a misfire is prevented.