To provide a rain sensor device for detecting rainfall regardless of a property of rainwater or the like, and improving detection accuracy of rainfall.

The rain sensor device 10 includes: a first rain detection means 12 on which an electrode installation surface 22 is formed, for detecting rainfall by utilizing an electric action of rainwater wetting the electrode installation surface 22; and a second rain detection means 14 having a converging part 34 installed on a peripheral position just under the first rain detection means 12, and converging at least rainwater flowing down along an electrode 20 part of the first rain detection means 12, for detecting rainfall by utilizing the weight of the converged rainwater.

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