An image pickup apparatus having extendibility. The image pickup apparatus includes a front case that forms an apparatus appearance, a rear case that forms the apparatus appearance with the front case, and panel members. At least one of the front case and the rear case has arms that extend in a direction approximately parallel to an optical axis of the image pickup apparatus and that are united with at least one of the front case and the rear case. The front case and the rear case are connected through the arms. The panel members are fixed to the front case and the rear case so as to cover openings formed in a state where the front case and the rear case are connected through the arms.