A distributed phase type circular polarized wave antenna is composed of a group of narrow conductor lines 2a, 2b, 2c and 2d, and the group of the narrow conductor lines 2a, 2b, 2c and 2d are laid out in a two-dimensional plane. Complex vectorial sums of respective projections of current induced in each point of the narrow conductor lines 2a, 2b, 2c and 2d in two directions orthogonal to each other in the two-dimensional plane are determined, such that amplitudes of the complex vectorial sums are equal to each other in the two directions and a phase difference between the complex vectorial sums in the two directions is 90°.