A high-frequency device that detects biological information related to heartbeat, respiration, and the like with high accuracy. A high-frequency device (1) includes a biological signal extracting unit (heartbeat signal extracting unit 53, respiration signal extracting unit 63) that extracts a biological signal representing a specific frequency component; and an autocorrelation function processing unit (heartbeat autocorrelation function processing unit 54, respiratory autocorrelation function processing unit 64) that determines periodicity of an autocorrelation function to calculate biological information.