Horn switch device, airbag system, and steering wheel

To provide a horn switch device in which the contacts can easily be positioned to each other, so that the assembly to an airbag system is easy. A horn switch device (70) includes a first contact member (71), a second contact member (72) disposed to the first contact member (71) via a spacer (74), a guide shaft (50) for guiding them, a coil spring (90), a contacting body (85) at the distal end of an extension (16) extending from a retainer (10), etc. When a module cover (40) is depressed, the second contact member (72) comes into contact with the contacting body (85) to be deformed, bringing the contacts (81 and 82) into contact with each other to sound the horn.