PURPOSE: To adjust a sensor case in the direction of a human body even when the titled visitor annunciator is fitted at any height by freely-rollably fitting the base sensor case.

CONSTITUTION: By fareely-rollably pivoting a sensor case 4 for a base 2, the angle of the sensor case 4 can be freely adjusted to turn to the face of th4e human body when a visitor annunciator 1 is fitted at any height. An inner cylinder installed with a sensor is freely-turnably installed in respect to the sensor case. Thus, a condition, in which an annunciation signal is generated when the human body passes from a right direction in a left direction, can be easily switched to the condition, in which the annunciation signal is generated when he passes from the left direction to the right direction, and when the human body passes in the orthogonal direction in respect to a passage, the annunciator is adjusted so as to generate the annunciation signal.