There is provided a monitoring camera apparatus which, while ensuring waterproofness, can perform focus adjustment when a dome cover is mounted. A lens (3) is covered by the dome cover (5) which is removable. A focus adjustment mechanism (9) moves an imaging device (7) in an optical axis direction and thereby performs focus adjustment. A setting button (13) being a focus setting operation unit is arranged in the inner side of the dome cover (5), and operated when the dome cover (5) is mounted. A controller (11) controls the focus adjustment mechanism (9). The controller (11) allows the focus adjustment mechanism (9) to start focus adjustment when a predetermined focus start wait time has elapsed after operation of the setting button (13). The focus start wait time is set according to a standard mounting operation time required to mount the dome cover (5).