The present disclosure relates to a radar apparatus and an antenna system for the radar apparatus. A first transmitting antenna group and a first receiving antenna group are constituted by elongating some of a plurality of transmitting antennas and a plurality of receiving antennas in a first direction of vertical directions, a second transmitting antenna group and a second receiving antenna group are constituted by elongating the other antennas in a second direction opposite to the first direction, transmitting antennas to transmit transmission signals and receiving antennas to receive reflection signals reflected from an object are appropriately selected, thereby being able to improve horizontal and vertical angular resolving power in both of mid/long-range sensing and short-range sensing.