A valve control apparatus of a diesel engine (1) is provided with an EGR valve (30), which is provided in an EGR passage (26) of the engine (1) and varies the flow rate of exhaust gas flowing through a passage (26) by carrying out an opening and closing motion, and an actuator (28), which executes a sticking avoiding operation for dissolving or preventing a sticking of a valve (30) by causing the valve (30) to move to and fro so as to open and close the valve (30) by a predetermined moving amount respectively in one direction and the other direction near a full-close position of the valve (30). The apparatus inhibits the sticking avoiding operation by the actuator (28) when an ignition OFF operation is carried out without starting an operation of the engine (1) after an ignition ON operation is carried out. As a result, it is possible to prevent a useless valve opening and closing motion and achieve power saving.