A driving mechanism, mounting to a flush apparatus, includes an actuation housing coupling with a valve body, a manual actuation unit including a push button and a manual plunger arm transversely extended from the push button towards a pushing platform, and an automated actuation unit including a motorized unit and an automated plunger arm transversely extended towards the pushing platform. When the push button is manually pressed, the pushing platform is pushed by the manual plunger arm to move a diaphragm member at the unsealed position. When the motorized unit is activated in responsive to a presence of a user, the automated plunger arm is driven by the motorized unit to move towards the pushing platform, such that the pushing platform is pushed by the automated plunger arm to move the diaphragm member at the unsealed position.