A vital sign signal processing device having an excellent detection accuracy of a vital sign signal is provided. A vital sign signal processing device includes: a plurality of vital sign signal detection units configured to detect vital sign signals of a subject; and a signal processing unit configured to process the vital sign signals detected by the plurality of vital sign signal detection units and to acquire vital sign information denoting a vital phenomenon which is movement of a living body. Each of the plurality of vital sign signal detection units includes a transmission unit configured to transmit a radio wave with which the living body is irradiated and a reception unit configured to receive a signal corresponding to a radio wave reflected off the living body, and each of the plurality of vital sign signal detection units is configured to detect the vital sign signal from the signal received by the reception unit.