Simultaneous recording in wide-ranging brain areas requires a wide yet adjustable horizontal inter-electrode distance. Microdrives proposed by previous studies have limitations in this regard. This study proposes a microdrive that accommodates two individual drives with adjustable inter-electrode distance in the horizontal axis, which extends the maximum inter-electrode distance in the horizontal axis and increases usage flexibility. The size of the electrode holders was increased to extend the maximum horizontal inter-electrode distance. The electrode holders are aligned vertically to decrease the size of the microdrive. The stability of the structure was increased by integrating the electrode holders, screws, and a supporting rod into a triangular prism. This configuration is compact and stable. The horizontal inter-electrode distance can be adjusted from 0.8 to 10 mm (or even wider) depending on the user’s requirements. The moveable microelectrode set is small and light, with a weight of only 2.8 g and a height of 25 mm. The performance of the device was verified using simultaneous recordings of multiple single-unit activities in the diencephalon and cerebellar cortex of a freely moving rat.