A detection device includes a driving circuit which drives a vibrator, and a detection circuit which detects a desired signal. The driving circuit includes a current-voltage conversion circuit which receives a feedback signal, and performs a current-voltage conversion, a drive signal output circuit which amplifies an input voltage signal after being subjected to the current-voltage conversion, and outputs a drive signal of a sine wave, and a gain control circuit which controls a gain of amplification of the drive signal in the drive signal output circuit. When a resistance for a current-voltage conversion is set to RI, the gain of the amplification of the drive signal in the drive signal output circuit is set to K, and an equivalent series resistance in a fundamental wave mode of the vibrator is set to R, the gain control circuit performs a gain control such that K×RI=R is satisfied.