To provide a plane antenna which includes stable antenna characteristics, is stably manufactured without lowering manufacture yield and shortened in its height.

A plane antenna 8 is equipped with a substrate 1 with which a radiation electrode 2 is formed on its front surface and a ground electrode 3 is formed on its rear surface, and which further includes a through-hole 7 from the front surface to the rear surface, and a power feeding pin 6 which is inserted into the through-hole 7, and of which one terminal is connected to the radiation electrode 2 by a solder 5 and the other terminal is protruded from the rear surface. The inflow quantity of the solder 5 for connecting the power feeding pin 6 to the radiation electrode 2 in the gap between the power feeding pin 6 and the through-hole 7 is 30 vol.% or less.