A focal point detection device includes a focal point detection section which detects a focal point state of an object image corresponding to each of focal point detection regions. A group selection section selects focal point detection regions as a group. A judgment section determines a focal point detection region in which detection of the focal point state is enabled in the selected group. An automatic focal point detection region selection section selects, when detection of the focal point detection regions can be performed in the selected group, a focal point detection region in the selected group, and selects, when detection of the focal point detection regions cannot be performed, a focal point detection region outside the selected group. A control section drives an imaging optical system in accordance with the focal point state corresponding to the focal point detection region selected.