Abstract: A microstrip antenna (100) having a ground patch (40) on which at least a feed line (30) is located, and a dielectric (50) laminated on the ground patch (40). The microstrip antenna (100) includes a left radiation patch (61) short-circuited to one end of the ground patch (40) and laminated on a left upper surface of the dielectric (50), and a right radiation patch (62) short-circuited to the other end of the ground patch (40) and laminated in an array on a right upper surface of the dielectric (50) with a radiation slot (70) arranged between the left and right radiation patches (61 and 62) so that capacitance is implemented between the left and right radiation patches (61 and 62).