An illuminated push button switch includes a manipulation knob, a hollow slider, a casing, which vertically guides the slider, a switch element, which is operated by the vertical movement of the slider, and a light source. A front end portion of the slider protrudes forward from the casing. The manipulation knob includes: a body; a skirt portion, which protrudes backward from a peripheral edge of the body and surrounds the front end portion of the slider; connection pieces protruding backward from a rear surface of the body more than the skirt portion and inserted into the slider; and locking holes provided in the connection piece. An inner wall surface of the slider is provided with locking claws which are snapped into the locking holes of the connection pieces so that the manipulation knob is snap-connected to the slider.