An occupant information sensing device 100 includes a plurality of heater electrodes that are provided at a vehicle steering wheel 104 and insulated and separated from one another and that generate heat by conduction； first heater power sources 118a and 118b of an insulated type DC power source that feed power to at least two heater electrodes 106 and 108 of the plurality of heater electrodes； and a heartbeat detecting circuit 124 that is connected to the heater electrode through a capacitor 124a and processes heartbeat signals 136 and 138, which are occupant information signals output from the heater electrodes.
