An image pickup apparatus capable of achieving in-focus photographing with a reduced time lag. A system controller of the image pickup apparatus detects an in-focus state of image while moving a focus lens in an optical axis direction, and detects a state of a photographing scene at image acquisition. When detecting a change in photographing scene, the system controller moves the focus lens to a movement start position. When detecting that a photographing scene has been decided by a photographer, the controller detects an in-focus state while moving the focus lens.