To provide a gyroscope installation method and a gyroscope device for using the gyroscope having a small FS value for an application for requiring a large FS value.

Two gyroscopes 2-1, 2-2 or more are installed so as to cancel a rotation signal in the direction orthogonal to a rotational axis Z of a rotator. In the gyroscopes 2-1, 2-2, angles θ1, θ2 between the rotational axis Z and measurement axes z1, z2 meet formula (1) |cosθi| < |FSi/ωMAX|. In formula (1), θi (deg) is the angle between the measurement axis of the i-th gyroscope and the rotational axis of the rotator, FS i (deg/s) is a full scale of the i-th gyroscope and ωMAX (deg/s) is the maximum angular velocity of the rotational axis of the rotator.