Abstract: A push button switch 1 comprises: a push button 10 that can be pushed in; a movable contact 120 that is linked to the push button 10; and a fixed contact 121 that comes into contact with or separates from the movable contact 120 by operation of the movable contact 120. The push button switch 1 further comprises a light-emitting element 130 for emitting light, and a light-receiving element 131 for detecting light. The light-receiving element 131 is disposed so as to detect the light emitted from the light-emitting element 130 and reflected by an object within a prescribed region. The push button switch 1 outputs an ON signal if the push button 10 has been pushed in, thereby causing the movable contact 120 to come into contact with the fixed contact 121, or if it is determined that the light-receiving element 131 has detected light reflected by an object.

Abstract: A limited reflection type sensor which irradiates exit light from a light emitting unit toward an object sensing region through an exit light lens and receives, at a light receiving unit, reflected light from an object existing in the object sensing region through a reflected light lens, may include a casing including a latching portion formed on a side surface and a first opening facing the object sensing region, the casing accommodating the light emitting unit and the light receiving unit; and a lens part including a light incident/exit part formed integrally with the exit light lens and the reflected light lens, and a side surface covering part in which an end of the light incident/exit part is extended along the side surface, in which the lens part covers the first opening with the light incident/exit part and the side surface covering part is latched by the latching portion.