An electronic circuit unit includes a multi-layer substrate in which high frequency circuits are provided on two different layers and a ground layer is formed between the two layers, and grounding lands connected to peripheral conductive members through connection bars formed on a plurality of layers of the multi-layer substrate. The grounding lands are connected to each other through a via hole and conducted to the ground layer, and the connection bars protruding radially outward from at least two grounding lands provided on different layers are arranged in different directions with respect to a circumferential direction such that the connection bars do not overlap each other along a thickness direction of the multi-layer substrate.