A digital phase shifter in which a plurality of digital phase shift circuits are connected in cascade. One of the digital phase shift circuits includes at least a signal line, a pair of inner lines provided at both sides of the signal line, a pair of outer lines provided outside of the pair of inner lines, a first ground conductor connected to each first ends of the pair of inner lines and the pair of outer lines, a second ground conductor connected to each second ends of the pair of outer lines, and a pair of electronic switches provided between each of the second ends of the pair of inner lines and the second ground conductor. The pair of outer lines adjacent to each other are separated between the digital phase shift circuits adjacent to each other and the first ground conductor and the second ground conductor adjacent to each other are separated between the digital phase shift circuits adjacent to each other.