To provide a sound field informing device informing the optimum viewing position of a viewing in a solid sound field.

Ultrasonic wave signals are emitted from the signal generator 10 of a remote controller to position sensors 6L and 6R provided for speakers 5L and 5R positioned more right and left than the viewing positions 11a, 11b and 11c of the viewers. Distances from the viewing positions 11a, 11b and 11c to the left/right speakers 5L and 5R are obtained in a micro controller 7 from the time difference of the signals received in the sensor 6L and 6R. A display position 9 displays whether the viewing positions 11a, 11b and 11c are positioned on a sweet spot 12 or they are dislocated to the left side or the right side from the difference of the distances.