A button unit for an electronic control apparatus of a vehicle is disclosed. The button unit comprises a button and a detector. The button comprises a controlling portion which is pivotably coupled to a front panel of the electronic control apparatus, and an extension bar which extends from the controlling portion into the electronic control apparatus to be pivoted in a direction opposite to the pivoting direction of the controlling portion. The detector comprises a switch which is located within a pivoting radius of the extension bar and can be pivoted under the action of the extension bar, and a detector body on which the switch is pivotably installed and configured to transmit at least a electrical signal to the outside according to pivoting angles of the switch.