To provide a quiet suction device for a vehicle dispensing with a power supply for suction and preventing exhaust air from suction process from being discharged inside a vehicle cabin.

This on-vehicle suction device 1A installed in the vehicle 100 is provided with a collecting device 4, when sucking and collecting sucked matters, making its inside into a negative pressure; a suction tube 6 having a suction inlet having one end opened to the collecting device and the other end opened to the outside of the collecting device and performing the sucking through the suction inlet 6A by the negative pressure in the collecting device 4; a vacuum hose 3 communicating the collecting device 4 with a suction system 12 for giving the negative pressure of the suction system 12 of an internal combustion engine 10 of the vehicle 100 to the collecting device 4; a pressure regulator 5 provided in the vacuum hose 3 and regulating the pressure in the collecting device 4; and an opening/closing valve 7 provided in the vacuum hose 3.