An intercooler device of a supercharged internal combustion engine, the intercooler device comprising: a low temperature-side tank; an outlet pipe extending from the low temperature-side tank; a reservoir provided in a lower part of the low temperature-side tank and temporarily collecting condensate water; and a water suck-out pipe extending from the reservoir to a position at which the water suck-out pipe opens inside the outlet pipe, wherein an appropriate amount of condensate water is sucked out from inside the reservoir through the water suck-out pipe while the internal combustion engine is idling, a constriction that inhibits an excessive amount of condensate water from being sucked out through the water suck-out pipe while a throttle valve of the internal combustion engine is fully open is defined in a condensate water discharge passage formed inside the water suck-out pipe, the water suck-out pipe includes an upright part that has a portion opening at a bottom of the reservoir and extending in an upright direction, and a lateral part that is connected to an upper end of the upright part, extends in a lateral direction, and opens inside the outlet pipe, characterized in that an outer diameter of the lateral part of the water suck-out pipe is larger than the outer diameter of the upright part thereof, and is set to such a diameter that a pressure for sucking out the appropriate amount of the condensate water while the internal combustion engine is idling is created in a supercharged air passage part defined between an outer surface of the lateral part and an inner surface of the outlet pipe, and a central axial line of the lateral part of the water suck-out pipe is placed coaxially with a central axial line of the outlet pipe. a low temperature-side tank; an outlet pipe extending from the low temperature-side tank; a reservoir provided in a lower part of the low temperature-side tank and temporarily collecting condensate water; and a water suck-out pipe extending from the reservoir to a position at which the water suck-out pipe opens inside the outlet pipe, wherein an appropriate amount of condensate water is sucked out from inside the reservoir through the water suck-out pipe while the internal combustion engine is idling, a constriction that inhibits an excessive amount of condensate water from being sucked out through the water suck-out pipe while a throttle valve of the internal combustion engine is fully open is defined in a condensate water discharge passage formed inside the water suck-out pipe, the water suck-out pipe includes an upright part that has a portion opening at a bottom of the reservoir and extending in an upright direction, and a lateral part that is connected to an upper end of the upright part, extends in a lateral direction, and opens inside the outlet pipe, characterized in that an outer diameter of the lateral part of the water suck-out pipe is larger than the outer diameter of the upright part thereof, and is set to such a diameter that a pressure for sucking out the appropriate amount of the condensate water while the internal combustion engine is idling is created in a supercharged air passage part defined between an outer surface of the lateral part and an inner surface of the outlet pipe, and a central axial line of the lateral part of the water suck-out pipe is placed coaxially with a central axial line of the outlet pipe.