Radar device

A radar device comprising:

• a case having an opening at a front of the case in a forward direction, which is a transmission direction of an electromagnetic wave;
• a circuit board placed in the case, the circuit board having a first circuit board part and a second circuit board part, one component side of the first circuit board part being oriented in the forward direction, component sides of the second circuit board part extending along the forward direction;
• an antenna section composed of a plurality of antenna elements placed on the one component side, oriented in the forward direction, of the first circuit board part, the plurality of antenna elements being placed into an array in a direction crossing the forward direction, the antenna section sending an electromagnetic wave to an outside of the case through the opening, the antenna section receiving a reflected wave of the electromagnetic wave;
• and
• a dielectric lens that is a semi-cylindrical or parabolic cylindrical lens having a convex shape in the forward direction, the dielectric lens being placed in the opening in the case so as to extend along a direction in which the plurality of antenna elements are placed into an array.