An automobile knob switch assembly comprising an operating lever 1 that has a shaft rod 1a. A terminal plate 2 is inserted into an opening part if of the operating lever 1. A movable plate 3 has a movable contact plate 13 that contacts the stationary contact plates 8 placed in the terminal plate 2, a through hole 3a through which a cylinder part 4a of a moderator 4 is inserted, and latching pieces 3b that are latched onto the moderator 4. The moderator 4 has an elastic claw 4c that is latched onto the shaft rod 1a. A knob 5 has a latching part 5b that is engaged to a latching piece 3e formed in the periphery of the movable plate 3. A second embodiment is disclosed that has two knobs for the rotary switch installed at the tip of the operating lever 15. The construction of the knob switch assembly permits the parts of the switch assembly to be automatically assembled with machines for mass production and reduced costs.