A microphone support device includes a ring-shaped flame, a plurality of fixed arms which protrude toward an inner side of the flame, a plurality of movable arms which are longer than the fixed arms and are detachable, and multiple microphones. A small-size microphone array is constructed by accommodating the plurality of movable arms inside of the flame in a radiating state. On the other hand, a large-size microphone array is constructed by radially developing the plurality of movable arms outside of the flame. When constructing a circular two-dimensional microphone array, a size of the circular two-dimensional microphone array can be easily changed in this manner. Hence, the sound localization can be handled over a wide frequency range.