An in-vehicle device for detecting a driving condition includes: first and second sensors for detecting one of acceleration and angular speed; first and second determination units for determining whether a detection signal from each sensor is varied with a frequency equal to or larger than a predetermined determination frequency and with a variation amount larger than a predetermined variation threshold; and a vibration noise removal unit for determining that a vibration noise is superimposed on each detection signal. The vibration noise removal unit removes the vibration noise from each detection signal.