[Problem] To provide an engine control device in which a desired valve can be opened or closed during a transition between reduced-cylinder operation and all-cylinder operation. [Solution] Provided are a valve stop mechanism (25a) that can switch intake-exhaust valves (8, 9) of resting cylinders (2A, 2D) between an openable/closable state and a held-closed state, and an engine speed control unit (55) that controls the engine speed. In a case where after the engine speed control unit (55) has received a request to shift from one to the other of reduced-cylinder operation and all-cylinder operation, and a specific condition is met, i.e., that switching by the valve stop mechanism (25a) has not been completed and the connection between an engine and a drive transmission unit has been released , the engine speed control unit (55) controls the engine speed so that the amount of change over time in the engine speed is less than a case where the specific condition has not been met.